It's fine.

Like any CMS, it has a seemingly constant low level of patching to be applied. The more third party modules and themes you have, the worse that gets.

Remove unused modules that aren't core. Same with themes. That'll make things easier.

Otherwise it's overheads are just Apache/nginx, MySQL/MariaDb, and maintenance of the TLS certificate, plus OS patching. All fairly well understood stuff that you should have no issues with.

Drupal is a bit of a beast. It takes a lot of experience to keep one of these alive over time when major version updates will break plug-ins and custom code. I’d recommend either keeping it very vanilla or having a “guy” who’s either a drupal dev or has some experience with migrations. It’s fine to self-host, but handling those upgrades isn’t always easy.

I’d say try to push Wordpress as much as possible, and only go drupal if you absolutely need the features, but try to avoid customizations that add schemas or complex data structures.