You might be right, I always wondered if it was the software or program (Friuty loops) rather than the actual mixing or mastering. The engineer has nothing to do with it. I was never a huge fan of FL. Always like ProTools more.....sounds more professional.
The fact that Hit also ain't a vinyl head like Primo or Alc and he's not directly sampling from the vinyl probably affects the sound quality.
Or that the sample packs and plugins for Fruity Loops are inferior to other sample packs for Pro Tools or Reason.
It has nothing to do with the DAW. I think the studio standard for mastering is still running the stems through Pro Tools anyway, so even beats made on FL get run through Pro Tools in the end. People are not using Pro Tools to make beats like that. Not to mention that todays FL Studio is not the same as Fruity Loops from 15 years ago as far as capabilities go.
Sampling off vinyl is said to have a warmer sound, but with the technology available today you can pretty much dirty up any sample from anywhere to add the warmth in. Madlib famously said he samples from Youtube all the time. It's not really a hurdle like that any more.
Also, sample packs are not exclusive to certain DAWs. You can use sample packs with any DAW.
It's just the way Hit Boy and his engineer choose to have the track sound. It's nothing more than that. IMO it seems like they're trying to go for a really clean sound, but that takes away from the boom bap aesthetic for a lot of these tracks. You need all the dynamics in the mix to give it the full sound with boom bap. It's all about atmospheric samples that create emotional reactions paired with hard hitting fat drums that meld with the sample to create something with a lot of soul. Trap is pretty much the opposite. It's about clean sound where every sound feels disconnected and the drums are sharp and tinny. Hit Boy is taking that trap aesthetic and applying it to boom bap and it's losing something because of it IMO.
Check these out.
Here is Hit applying trap aesthetic to a boom bap style beat.
Here is Alchemist applying boom bap aesthetic to a trap style beat
The trap aesthetic does work better for car speakers and club type sound systems because the separation of the cleaner, more consistent bass notes. Boom bap works anywhere IMO but it works especially well in headphones where all the different textures melding together creates a really full sound where the full spectrum of frequencies is covered. There's always exceptions to the rules and variations where these aesthetics are all shuffled up together, but for the most part that's the norm.
That's my take as a self taught hobbyist producer, at least.