Debian minimal netinstall should fit you use case. Long support time, small footprint and should support everything you want to do. Just secure it by having a unprivileged account doing all the stuff you want to do.

With that amount of ram you could make it a hypervisor and host a lot of containers and vms. Maybe proxmox would be a good fit?

Wow thanks. Was missing that for a long time.

Firefox would give me weird problems with teams in the past. Have not tried it in a while though. I’ll try it and if it works without problems now I’m happy to leave chromium behind.

For teams specifically I’m just using the web version with chromium. Installed as a chromium app so I have quick access to it and have it on my taskbar. Rest of Office 365 works just fine in any browser. (Outlook, SharePoint, Power apps etc) For OneDrive Sync you can use https://abraunegg.github.io/ which should work on most distros.

Take a look at simple Android TV boxes with a USB port. There are plenty of options and you can just install vlc on them

Get a used Thinkpad. Shop around eBay for a T480 or T490 which should be at that price range. Solid machines with great Linux compatibility. Anything new will be much worse at that price point. If you desperately searching for something new maybe a HP 255 G9 with a Rzyen 3 would be fitting. Not as good built quality wise and I’m not sure about Linux compatibility but at least it is upgradable. (https://h20195.www2.hp.com/v2/GetDocument.aspx?docname=c08017466)