All metal tubs are still a thing, you just wont find them at the big box stores often
These days you have more choices, so picking what your work requires is important.
_______________ Traditional Shop Vac_______________________________ Dust Extractor________________
Are you sucking up rocks from the bottom of a trench OR vacuuming up after small messes in a tidy shop
Ridgid is still the kind of big brute, big hose, beat the hell out of it grunt work- they do offer a metal tub version
Theres also now "Dust Extractors", more of a finer approach to vacuuming, typically smaller diameter hoses, quieter, better layout, on/off tool outlet, auto-filter, better accessories, expensive. Great for some, not needed for others.
Personally I think the sweet spot currently is DeWalts Stealth series with tool activation outlets- Big, heavy duty, cheap, with good features