It's been 11 years of this--what's changing in a few more months?
It's just anecdotal . . . but I feel the same way. There has certainly been a lot of 5E material put out all the way back to 2014, but relatively recently there feels like an uptick. I mostly notice this on Kickstarter, where there are a LOT of 5E projects constantly churning through.
I do play 5E, it's my game of choice. But I've also found myself a bit exhausted at the volume of 5E products being made available. Is it truly more than before? Or has the marketing gotten "better" so it's feels constantly in my face?
Most of the projects I click on seem to be successfully meeting their crowdfunding goals. There seems to be a lot of "slop", mediocre quality projects that don't seem all that different from other projects, but there also seems to be an increase in interesting, different, and high-quality projects, often by a wider variety of creators that have been available to the American market before. Some really good stuff coming out of France and Italy, and other corners of the globe.
Is this good or bad? A mix of both, IMO. A lot more slop to wade through, hence the "exhaustion" as a consumer. But a lot more gems within the slop too. Although, it can sometimes be hard to judge until after you've pledged towards a crowdfunder, and received your books, of course.
I haven't stopped backing or purchasing 5E compatible game books . . . but I've become a lot more wary and careful in considering which projects to back, or which products to buy.