That depends on what you mean by “real game dev”. I did a few game things of my own in BBC BASIC, eventually with a bit of 6502 assembly in key places, back in the day. On those machines you can still happily run a basic game loop in interpreted BASIC, the whole thing for text-based games, you just need to get down to the bare CPU for things like sprites, other rapid graphics drawing, and maybe some other number crunching (I did some basic compression in assembly for lots of text, though it wasn't really effective, if you are already doing graphics in assembly, then it probably makes sense to do collision detection and such there too, etc.).
replyC64 BASIC is kind of a mess, there's zero support for graphics and sound. Your code rapidly becomes a giant pile of POKEs and PEEKs, and all your operations become absurdly slow because all the math routines are floating point only, so there's a ton of integer/fp conversion overhead on something as simple as "peek a memory location, AND/OR it with a few values taken from variables stored as floating point, poke it back".
replyAssembly becomes really attractive really quickly.
BBC BASIC was far better than C64 BASIC.
replyIt had a nice set of built-in graphics functions and an inline assembler, amongst other things.
I can still remember that VDU 23 was the command to redefine a character, so much easier than doing the same sort of thing on the C64 (copy the character set from ROM to RAM, get the VIC to use the RAM copy with POKE statements, modify the desired character)