Hi, Apple says the following about Metal 3:
Metal 3 is supported on the following hardware:
iPhone and iPad: Apple A13 Bionic or later
Mac: Apple silicon (M1 or later), AMD Radeon Pro Vega series, AMD Radeon Pro 5000/6000 series, Intel Iris Plus Graphics series, Intel UHD Graphics 630. [1]
For the iPhones and iPads: All iPhone 11 models + SE second generation and later. iPad (9th gen), iPad Air (4th gen and later), iPad mini (only M1), iPad Pro (probably only those with M1 - if we are lucky A12X and A12Z too because they have more raw power than A13, but I would not bet on that).
When we look at the spec sheets of the Macs: all Apple Silcon Macs, Intel MacBook Pro 13", 15" and 16" (2017 and later), Intel MacBook Air (2019 and later), iMac (some 2019 models and later), MacPro (2019 and later), MacMini (2018 and later), iMac Pro (2017 and later).
This list matches perfectly with macOS Ventura (Except the MacBook 12" from 2017).
Therefore, I would argue: When you can get Ventura, you get Metal 3. [2]
[1]: Apple Metal 3 Developer
[2]: macOS Ventura