Some do like 50mm and 56mm lenses on 8x and 10x binos but most don't, that's why 8x42 and 10x42 are the top selling binos and large diameter options are limited.
I've had several 8x and 10x 50mm and 56mm binos too. They did nothing 42's didn't and were just huge. 56's I want mounted on a tripod and with 15x behind them. I also don't believe theres any issues with the 4.2mm exit pupil on a 10x42, in fact I much prefer my NL 12x42's in that aspect over my EL 8.5x42's despite having a 20% smaller exit pupil at 3.5mm. I sit for hours on end watching birds and animals with my NL 12's and I'm definitely someone thats very prone to eye fatigue. Matches are loaded with 15x56's that spotters sit behind for most of the day glass with with have a 3.7mm exit pupil. Look what most western hunters are using. So I think it's reasonable to agree that most people don't have an issue with that.
You'll also find that many larger objective lens versions have smaller FOV too. Look at the 8x Geovid Pro's as a perfect example. The 32mm has a 405ft FOV, the 42mm a 390ft FOV and a 387ft FOV for the 56mm. The pros also aren't light binos either, the 32's are 30.7oz, the 42's are 34-35oz and the 56 is 42oz so the weight it also there. I know weight is very personal but you'll find that most people prefer binos in the 20-30oz range for offhand use, the lightest models start at that.