Disclaimer: I'm no Inkscape developer or contributor, just a long-time user

Maybe I'm being picky but I hope that's not what you were told word for word, otherwise you may have a long road ahead before you can convince them:

• The quoted phrase seems erroneous, although we understand they meant "risks of using freeware outweigh its own benefits compared to using in-house software".
• As far as I know, unless your work place is Adobe, then Illustrator is not its "in-house" solution. In-house means your company is developing its own software.
• Inkscape is not freeware. It's free and open source, fundamentally different and not to be confused.

That said, what kind of "risks" are they concerned about? Is it stability? Security? Usability? Features? The learning curve? All of those?
It would be much better for you to know how they use Illustrator in details and what they would be concerned about if they were to switch so you can give them a more informed answer.
Also I think it would be hard for us to give you a clear answer if we don't know what kind of visuals your company produces. Is it web content? print content? logos? documents? Something more artistic or more technical?

EDIT: Seems we got played by a spammer. Now there are ads in the original post. 💀

FWIW:

Here's a professional designer that uses both Illustrator and Inkscape for a world-renowned magazine.

http://www.segtsy.com/2013/07/never-boring-with-bohr/

I used the tweak tool in Inkscape. If it wasn't for that tool, I'd probably still be rotating atoms one at a time in Illustrator. Thanks to all the people who make Inkscape possible. It's a wonderful tool.

https://alpha.inkscape.org/vectors/www.inkscapeforum.com/viewtopica90e.html?t=16801

BTW, Inkscape is Free Open Source Software, not freeware. Big difference.

Q: Are "non-commercial software", "freeware", or "shareware" the same thing as open source software?

No.

Do not mistakenly use the term "non-commercial software" as a synonym for "open source software". As noted above, in nearly all cases, open source software is considered "commercial software" by U.S. law, the FAR, and the DFARS. DFARS 252.227-7014 specifically defines "commercial computer software" in a way that includes nearly all OSS, and defines "noncommercial computer software” as software that does not qualify as "commercial computer software". In addition, important open source software is typically supported by one or more commercial firms.

Also, do not use the terms "freeware" or "shareware" as a synonym for "open source software". DoD Instruction 8500.2, “Information Assurance (IA) Implementation”, Enclosure 4, control DCPD-1, states that these terms apply to software where "the Government does not have access to the original source code".  The government does have access to the original source code of open source software, so these terms do not apply.

https://dodcio.defense.gov/Open-Source-Software-FAQ/#Q:_Are_.22non-commercial_software.22.2C_.22freeware.22.2C_or_.22shareware.22_the_same_thing_as_open_source_software.3F

TD

Hi there,

The problem was that there are not enough licenses available, you said. But when you talk about Inkscape, and the answer of the technicians is that there is an 'inhouse and available solution'... To me it seems that you can say that it is not available, because of too little licenses.

If your company uses this software, it is difficult to convince them otherwise. Adobe dominates the market, people are used to it and they are obliged to keep using it and pay big money for it.

I always like adding the numbers: 3 subscriptions x monthly fee x 12 months x 10 years. That number is very convincing in itself.

Most of the professionals using Inkscape are small companies, universities, teachers, hackerspaces and artists. It is always safer to use more programs, they all have their strenghts and weaknesses.

There is no reason not to have tools like Inkscape available on all computers. Even if you have access to Adobe software, there's no loss in having more tools available.

As for risk. Free Software is about greater freedom for users, but it's also about greater responsibility. I won't sugar coat the fact that when you have a program like Inkscape, all the risk is your own. BUT considering how monopolies like Adobe treat their customers, there's not a great material difference anyway. You are on your own, even with a business relationship with Adobe because they can get away with whatever they like and you don't have many options once your staff are trained in one (and only one) piece of software.

Stated in edit above:
Seems we got played by a spammer. Now there are ads in the original post. 💀

EDIT 5/31/20: Moderators have removed the ads and blocked the offending spammer.

It's an open source software, the source code is accessible for everyone and maintained by the community. If there's something fishy in it, the community would notice it.

The Inkscape website has a compressed version available. You unzip it to a folder and run the executable from there. This is "portable" in a way. Going to a business website that sells portable software and downloading a copy there is not anything I would recommend. I've seen it compiled incorrectly or with other problems on many occasions. If you want something "portable," stick to the original source. It's worth noting that launching an executable from an extracted archive isn't entirely what some people mean by portable. All of the config files should be held in the same directory as the executables. As a result, it's possible that the program will be run from a thumb drive. When you run the executable from the archive file, preference files are generated on the local computer, not on the thumb drive. The thumb drive's habits would not be carried over.

Areba21

preference files are generated on the local computer, not on the thumb drive

This is true for the 7zip version, not the portable app version. https://inkscape.org/release/1.0.2/windows/32-bit/