Wheelbuilding, though intimidating, has a much easier entry than you might think. It's my relaxation, and the smaller wheels are easier to true up.
You really just need a screwdriver and spoke wrench, and maybe a beer and set of googled how tos.
Its a skill you pick up as you ride more, if only just at the maintenance level (spoke and truing)
Getting a front derailleur on a foldy not set up from the factory , and keeping it happy, protected and adjusted, is a bigger deal than on a standard diamond frame.
Heel shifting without one is, um, inelegant. Costs for FD+crank+mount run ˜$80, for parts if you shop it.
Greasy finger shifting lacks broad appeal.
My goal was to get a closer set of gears, since you can get a pretty decent gear range without involving the front.
Getting the gear set up with something that suits you on any bike is a degree of customizing that all bike riders should embrace, it's just part of a good fit.