When I started the self hosted trip, I was against containers and tried to avoid them at all costs. Then I learned about containers, and now I still am against containers but less vividly so. I have used them and still use them.
Containers are good for the self hoster because they deliver fast deploy and easy testing of lots of services quickly. They are good for developers because they can provide one common installation approach that reduces greatly user issues and support requests.
But containers also have downsides as well. First of all they make the user dumber. Instead of learning something new, you blindly "compose pull & up" your way. Easy, but it's dumbifier and that's not a good thing. Second, there is a dangerous trend where projects only release containers, and that's bad for freedom of choice (bare metal install, as complex as it might be, need to always be possible) and while I am aware that you can download an image and extract the files inside, that's more an hack than a solution. Third, with containers you are forced to use whatever deployment the devs have chosen for you. Maybe I don't want 10 postgres instances one for each service, or maybe I already have my nginx reverse proxy or so. I have seen projects release different composer files for different scenarios, but at that point I would prefer to deploy on bare metal.
Said so, containers are not avoidable today, so study and embrace them, you will not be disappointed as its a cool piece of tech. But please stay clear of docker and go podman instead. Podman doesn't rely on a potentially insecure socket and does not require an always running daemon. Podman also by default doesn't force you to run services as root which you should never do. Also, networking feels clearer on podman and podman feels more .modern by using nft instead of iptables. Yes most of this can be fixed on docker, but since podman is a drop in replacement, why bother? Also, podman is truly open source while docker, shockingly, its not.
One last thought: updating containers should not be taken lightly. Its so easy and fast that you might be tempted to setup cron jobs or install watchtower, but you will end sooner or later with a broken service and lost data. So backup, always backup, and keep updating with rationale.
Tldr: containers are unavoidable today and are a cool piece of tech worth investigating. Don't blindly use them as there are security issues involved, and I hope the trend of making containers the only way doesn't take hold, because containers also make self hosters dumber and that's not good.