Good question, I had to think a bit about this before answering and I think it all depends on what people decide to do with music in the future. A good portion of the clients I get are people who have already tried doing everything themselves, or had a friend who wasn't very good at this work on the music with less than professional results.

A lot of times it takes people to go this route before they realize they need to hire someone who is better at this than them, but unfortunately, sometimes they approach people like me a little bit too late, or at a point where they aren't able to best utilize my services.

The biggest issue I'm seeing right now is the amount of over-processing people are already doing to their mixes (without having the necessary conversion and monitoring to make the best decisions). It's also typical to not be able to go back to the mix stage and make tweaks so often times, I have to work with mixes that are not optimal for mastering and under these conditions, it's impossible to get great results.

Hopefully in the future, people will be more aware and maybe even talk to a mastering engineer during the mixing stage, since consultation is part of the job (In all the time I've been doing this, I've only been asked to help oversee the mixing stage about three times). Just having a thousand plugins available doesn't mean you can get the same results as someone who has better conversion and more importantly, more experience at doing this.

I think people will eventually understand the above; I would say about 30% of the jobs I get are from people who say "if you need us to change the mix, just let us know" and I see this trend growing, which is great. Hopefully by the time you're ready to start your own mastering service, this will be common knowledge. Best of luck to you and thank you for the great question!