This won't change with the speed booster. The 32mm is a better quality lens. That said, if you want to get more EF lenses, then in the long run the adapter may be better. The 18-150 should be of similar use to the EF-S 18-135mm, which is already a pretty good lens ( not compatible with the speed booster, only normal adapter).
The biggest downside is that the RF mount's lens selection is still limited. Canon's strict third-party licensing means fewer overall lens options as Canon continues to build out its native lens lineup. However, you can adapt any EF lens perfectly using the EF-EOS R lens adapter, though it'll come at an additional cost. EF-S ultra wide zoom lens with an impressive starting focal length (16mm in 35mm equivalence).Compact design made possible by a new 4 group zoom optical system.A stepping motor (STM) and newly-designed focus mechanism support the Canon EOS Movie Servo AF function to provide smooth and quiet continuous AF during video recording, as well as when shooting photos.A large diameter element and an The EF-EOS R Mount Adapter is the standard version Canon makes, enabling you to fit your collection of old Canon EF or EF-S lenses to its new mirrorless full-frame RF mount bodies, such as the EOS R6. It’s also the most budget-friendly of the four adapters we look at here. The adapter increases the flange distance caused by having a mirror in Yeah, the adapter is a pain sometimes, but the (avoided) humongous price difference with RF lenses is well worth the pain of using the EF lenses with the adapter; and you can also feature many interesting third party lenses, with solution that are not available in RF and are 30yo (and sh*tty) in EF (50 f1.4 hellooooo).