Bill wrote:

What alternatives to TeamViewer are people using?

Where I can, I use reverse VNC so the person needing help connects to
me, so they don't need to dick about with firewall rules, and I can
hapilly se up port forwarding at my end, and it's not reliant on any 3rd
party's servers,

So, I don't use it much, but have used AnyDesk as a TeamViewer substitute.