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.
Will bitcoin ever solve scalability? It's now nearly two years since the fee and mempool problems of 2017 and still the mempool gets full even with much reduced transactions.
If bitcoin can't solve scalability, either cryptocurrency as a whole dies a death, or another scalable alt will take it's place.
Bitcoin can survive as an SOV alone with the currentl transaction limitations.
Gold as the precious metal dominant SOV would have very little transactions across a day, and I am certain the amount of transactions in gold per day can easily be matched and surpassed with current Bitcoin infrastructure.
A 2nd layer scaling solution like the lightning network is just a cherry on top.