Brompton's biggest problem is the number 20.
Other manufacturers have a huge head start with 20 inch wheeled bikes and there is some stunningly nice to ride machinery out there, even at a fairly tight budget.
The jump to 20 negates the supposed (and to my mind rather overrated anyway) benefits of the Brompton fold. Once done it's barely any more compact than a Tern type Z fold, so what's the point?
And the 20" wheels aren't that great off road. Sure, it'll do it, but then I've done some rough stuff on my ID9 which comes as standard with BMX tyres anyway. Brompton are touting the off road ability as its USP, but in reality there are already folders thst can do this, even if not touted as such. Not only that, its not good enough that you could buy a G Spot and throw away your gravel bike if trails are your thing.
Being tall and very heavy the original Brompton wasn't much use for me. For years ive wanted Brompton to make a 20 incher, but now the G Spot is here I find that the more-or-less simple scaling up of the idea doesn't work all that well.