Nah, it's not been about piracy for a while, and even when it was about piracy it wasn't just about piracy. PC development is inherently harder because there isn's a locked hardware target, so compatibility is difficult and expensive to service. And for a long time, PC sales were just much, much lower than console sales.

Both of those things have changed for a while, partially through the reduction of options in the PC market, partially through PC hardware manufacturers increasingly doing the job of servicing big games with dedicated drivers and partially through Valve becoming a closed, DRM-enabled platform more comparable to a console. You can chart that process, and it's long, difficult and full of ambiguity.

I have lots of thoughts on "game quality" as well, but it's hard to know what people even mean with that sometimes (bugs? design? content?). In general games today are... kinda great. Last year in particular was mind blowing. That said, games can get huge, expensive and complicated now in ways they couldn't really a few decades ago. But it's also true that games are more varied. Every game in 1994 looked more or less like every other game because the hardware could only do so many things. Today you can play retro 8-bit games AND effectively CG film-quality narrative experiences on the same hardware. It's crazy how expansive, varied and creative games have become.

Even if one thinks quality has gone down, though, it clearly isn't because of consoles.