I think that posting this here is going to be very biased. The few that have made the switch are no longer here or probably won’t respond.
I have been on Roblox for a while now. Almost 10+ years and while the Roblox engine has gotten far better over the years, it simply does not compete with Unreal or Unity. In fact, both of these engines are levels above Roblox.
When I made the switch, I did so because I was tired of the limitations. Everything that I needed was simply not afforded to me by Roblox. Things such as custom shader support, access to a more mature audience, etc. While I do agree that Roblox provides a strong base for learners, it’s main audience (kids) is what I really do not like. I have to abide by kids and parent rules. My genre or idea has to be dumbed down for kids to understand and had to be conform to a bunch of rules that I simply don’t care enough about.
For this reason alone, Roblox is a kids platform. It’s dominated by kids. It’s dominated by parents who police their kid. It’s dominated by rules specifically targeted to kids. Unfortunately, a game platform that hosts kids games is not taken seriously in the industry (one of which I am in so, I’d know lol).
Perhaps, a later time, this might be taken seriously but, for game developers who really want control and technical freedom… UE4 will always be the better route. I’d warn you though. There’s a learning curve and creating a game is much harder than it is on Roblox. However, once you learn and complete a game… it’ll be levels above what Roblox can provide for you. I’ve been using UE4 for about two years now and I absolutely love it. Though, it requires a decent computer at times. Depends on how graphics-intensive your game is.
No matter what engine you want, Roblox will provide you the quickest way to make a game. It’ll cut your time by a significant margin. However, the actual quality of your game will be nowhere near industry standards and will probably look or feel the same as every other game on the platform. For some people, this works. For some others, this doesn’t. All engines out there eventually take a cut of what you make. Unless you create your own game engine (which no one can really do in sufficient time), you won’t be able to escape it.
If you’re still learning, stick with Roblox. It’s a great platform to learn from and get a sense of where you want to be. I learned on Roblox before I pursued software as a career.
If you really want to be serious and drive quality, UE4 is so much better. Expect to put a lot of time.
In the industry, I think a successful game with UE4 would be far better for employers since you’d be doing it in C++ and C++ is used so much more in the industry. On Roblox, I really don’t know. I haven’t worked with anyone yet who has experience working on Roblox in the real world so, that’s really up in the air. I’d imagine that Lua wouldn’t be used as much… apart from being a middleware, embeddable type thing in some areas of the codebase. Plus, if you were making a top game on the platform… chances are that you wouldn’t be looking for a job elsewhere.
Sorry for this being long. I typed it out in a car.