What can/would you upgrade a SRAM GXP BB to? Have a SRAM GXP BB (68mm BSA) with some SRAM Apex 1 cranks. The driveside bearing is shot (which is ridiculous considering the bike's a year old, barely rolling around). Most people say it's not even worth trying to replace the bearings. I could just get another of the same type but I'd prefer to get something better. What would be a good upgrade to this BB? by upgrade I mean better quality bearings that last longer, more easily user replaceable if possible.
The SRAM Apex crank requires a GXP design bottom bracket., i.e. 24mm drive side and 22mm non drive side. That's not something you can change.
The GXP design is generally reckoned to be inferior to Shimano's Hollowtech II design because the non-drive side bearing floats and is not pre-loaded, unlike Hollowtech II where both bearings are pre-loaded. Source: Hambini YouTube Channel Caution! Lots of swearing and cussing.
However, you could look for a product with higher quality bearings than SRAM offers. There are several 3rd party manufacturers that make GXP compatible bottom brackets. Wheels Manufacturing for example.
You should also check the alignment of the threads in you bottom bracket shell. Angular misalignment of the bearings accelerates wear. One way check (at least for gross misalignment) is to remove the crank, then re-install. If the non-drive side end of the axle is not lining up exactly with the non-drive side bearing as the axle is pushed through the shell you have misalignment.