That being said, using an OS that is out of support is an invitation to get hacked. There are always problems with every system, but if it's not getting patches, then those problems become giant billboards of how to get in.
Look at upgrading to Windows 10 at least, or 11. Win10 is still in support at the moment, but its end-of-life date is getting close too. So if you'd rather not upgrade twice, hold your nose and go straight to 11. Then figure things out from scratch and rebuild your rig...before you're forced to anyway because someone randomly killed your out-of-date one, and about half your network along with it because that tends to be how attacks work. (find a weak point inside, even if it's not the target, and use that as a trusted internal source for the real attack)
Modern Windows actually runs on fairly old hardware. You might be surprised. Don't just write it off for that reason. I think there's even a way to get around Win11's requirement for hardware security.
Or, you can get some toy hardware and play with Lubuntu or Ubuntu Studio, as an evaluation to see if you can do the same with your production machine. I went there from Windows, and they're really not bad at all. Lubuntu is designed for slow machines, and Ubuntu Studio is designed specifically for live media, with a LOT of stuff preinstalled and already working, including OBS. I'd try UStudio first, since a machine that can handle live media anyway, can also do just fine with its slightly heavier footprint compared to most systems.
ubuntustudio.org
lubuntu.me
I'd stick with the LTS versions. (Long-Term Support) Those are released every 2 years and supported for 3, compared to the normal releases that come out every 6 months and are supported for 1 year. And wait towards the end of the current LTS support, before upgrading to the next LTS, just to let them work the bugs out of the new one. But DO get the new one, before the old one "falls off".