

Could browse as per normal with abysmal internet speed
Of course. It’s because they had to catch and write down every single byte with a pencil on paper, then decrypt it, understand it, report the funny ones to a boss, who nodded slowly and silently and then they typed it in again on the other side.
/s
Proxmox is (nearly) a class of it’s own. Yes, you need it.
You are not limited to lxc. Just run one or more of these Debians in VM’s inside, and they can docker then as needed.
Don’t forget to use the templates in Proxmox.