According to multiple debian based and ubuntu based and Arch I use. No. Not default. Cubic still is.
My experience was that some days ago I was trying to make my UDP faster, but turned out found out about BBR - for TCP. Well, lucky me - currently some country away from home for family reason. Plex generally takes 40-80s to start a movie/episode for me. And measly about 10s max buffer available - and this is on a 3-5Mbps show.
After BBR (note I have to apply on Proxmox host, my container are unprivileged and can’t set this themselves), I got 8-30s max to start a show/movie. And now comfortably sit between some good minutes on buffer. 15-20Mbps quality now playable.
To me personally it was black magic, and I was tossing it in just 2 days ago too
Ask more if question
Maybe not the right answer for you since I am not VPS-based but basement-rack-based.
I would choose Debian + docker for whatever available. Just make sure you have enough space for those. And probably even enough CPU.
To me it makes sense to separate them but some would argue otherwise with Docker/podman/container. Remember, Docker however by default is root.
The one I would actually do at home is Docker on a unpriviledged LXC (Proxmox) to make sure that there is no real root processes running
Cheers