However, I will concede that privacy has its own technical troubles, so coins like nano cannot yet be private on mainchain. Bulletproofs look promising. Tech develops and improves.
Exactly. Specialization is only good when it is necessary. Crypto communities like to jerk each other off about how special they are, but a lot of these specializations are arbitrary
If anything, the only real benefit these other coins have imo is to later have their specializations brought to Bitcoin somehow. With a few exceptions like LBRY.