Yeah. I don't believe that it has much effect, other than making it more likely that people would actually get to hear about paid DMing. Even if you were running an online game and had significant demand, you can't DM multiple games at the same time, and a game of D&D lasts upwards of three hours. You earn more flipping burgers in McDonalds. And on-line play makes it easier to find a DM who doesn't want paying.
As somebody who has been pro DMing for a couple of years now, and also acts as an agent matching players with at stable of other pro DMs, I can tell you that pro DMing is way, way more viable because of the internet. First off because of Covid of course, but just generally because your client pool is now the planet instead of your local area. There is also altogether less overhead running online than in person.
I know of nobody who has gotten rich as a pro DM, but most pro DMs do earn more by the hour than they would flipping burgers. Granted, some jobs flipping burgers might include benefits, but any freelance gig has that issue.
In terms of the hustle and self-marketing, I'm an actor and pro DMing is nowhere near as tough as that in terms of hustle required. If you're not used to gigging, I'm sure it seems like a nightmare. But if you are somebody who is already gigging, as gigging goes it's really not that bad.
It also has not ruined my enjoyment of the game as many here seem to fear it would. I will say this - my publicly advertised games open to anybody are all one-shots. I run long campaigns by invite only or by player request. So I'll only run long-term stuff with players I know well enough to see that they will not be a problem at the table. No amount of money imo is worth being stuck in a 1-2 year campaign with incompatible folks. However, internet evidence aside, 90% of players are great people.
I will also say that a good 1/3rd of clientele for pro games is kids, which I don't see a lot of people in this thread really focusing on. A group of parents will absolutely pay for a DM to run for a group of kids once a week, and in terms of activities you can pay for your kids to do, it's on the lower end in terms of cost and on the higher end in terms of being educational and fostering social skills.