Have to remember, people with no problems don't complain. So I think the number of problems is exagerated as that is all you see. Win 10 on literally 100;s of millions of PC's. not all of those are having problems or I wouldn't be saying this.
Win 8.1 doesn't have any support anymore, better to use 10 which is constantly being upgraded.
I can see no reason at all to go with Windows 8.1 over 10, as it is just kicking the can down the proverbial road.
Anyone who intends to stay in the Windows ecosystem for the long term will at some point be going to 10, as it is all that will eventually be in support. I have never found it useful to cling to any Microsoft (or any maker's, to be honest) product when said product has already been slated for end of life and it's replacement already exists.
You can also still follow the original upgrade process on Windows 7 and 8/8.1 machines to go to Windows 10 at no cost. I keep thinking that Microsoft has got to close this window, and they say that they have, but people have been continuing to use the technique and having success with it. If Microsoft permits it, and they're the ones that are the gatekeepers, then it's permissible.