is it profittable to open a server now?

Opening a server can be quite expensive, while you can use free/cheap plugins, hosts, builds, CMS, etc.
Not to mention, the EULA can cause a dip in profit considering that you are relying on pure kind-hearted donations or people buying cosmetics, this could be detrimental for some small servers. If you're starting out, use free plugins, and as you grow, start to use paid [or custom] plugins. If you have knowledge or skill in making plugins [or friends who do], why not give your server a unique identity and feel with a custom plugin?

tl;dr small servers, not much. especially including costs related with running and managing a server