Well, as you said, providing accommodation to clients for you is just one way to get a recurring income, it's not your daily work. Your daily job is to create websites and hosting them is only an advantage. The hosting configuration of a reseller is perfect for that: its providers handle everything that is related to the server, in addition to being hosted on very powerful servers (in most cases).
I can understand the desire to move on to something that is yours, but there is too much overhead associated with the placement, as others have already said in this thread.
A leased dedicated server is an option, but if you are not an expert in server administration, you will encounter almost the same problems as with the placement. A server management company is an option, but this will add more to the overall hosting bill.
There are dedicated servers managed, but each provider has their own definition of what exactly is "managed", so you should be careful. In addition, managed dedicated servers are more expensive than self-managed servers.
A VPS is a cheap alternative to a dedicated server and managed virtual servers are not that expensive. However, with more than 65 customers, you will need an expensive VPS and, at that time, the monthly price will be similar to that of a dedicated server.
In summary, if you are satisfied with your current location and do not want to convert "web hosting" into a more important part of the services you offer if you only want to concentrate on creating websites, stay with the hosting reseller. .