Experience with relatives who had no prior experience with Windows or Linux: installing Linux for them was great, painless and also facilitates troubleshooting for me. No problems here. Mostly using Linux Mint for those purposes, it's a great distro for non-techy people.

Experience with relatives with prior Windows experience (but no Linux experience): a mixed bag. Some use Linux happily now (thankfully), some returned to Windows because they couldn't change their habits or have weird specific incompatibility issues with niche hardware which they also don't want to solve in a different way. I've kind of stopped giving support to those, since I don't want to give Windows support in my free time. I sometimes have to do it work-related, that's more than enough Windows contact for me. I also refuse to give buying advice on any products by Microsoft, Apple, Meta, Amazon or Google, with only very few exceptions (e.g. Pixel phones, because they're very secure and with GrapheneOS installed they're the best general mobile phone option). It's a bit of an ethical dilemma because I'd like to help the people but also don't want to directly or indirectly support those companies. I always offer them help if they use Linux or the things I recommend.