Why are there so many new belt-drive turntables these days?

Turntables are popular again. Belt-drive turntables are much cheaper to make, so they fill the lower end of the market.

Even small manufactures can tool up to make a basic belt drive design. You could just about make your own if you were handy with the tools.

Direct-drive turntable design and manufacture is quite different and requires considerably more engineering and capital investment. The design, production and manufacturing costs are greater and this means that a decent direct-drive turntable is beyond the reach of many.