After 4+ years in the space and countless hours of research, it is becoming increasingly apparent that BTC is the only worthwhile project.
All your points are valid and I'm happy to see that there are users who understand the fundamentals of cryptocurrency instead of parroting the narratives created by altcoins' marketing teams.
I think that there are 2 kinds of altcoins that currently have some uses and as the result hold some value. The first type is privacy coins - Bitcoin's privacy is pretty bad, and the most common solution to it - mixers, requires some trust. If Bitcoin will solve privacy, privacycoins will become obsolete.
The second kind is coins with relatively good security and adoption. They can be used as a plan B when Bitcoin's fees temporarily skyrocket. They can be used for small transactions or for moving value between services to save on fees. But again, when Bitcoin will solve scalability, these coins will become useless too.