Yes. The fees are mostly due to bitcoin's unreasonable 1MB blocksize constraint. Most other cryptocurrencies do not have this problem because they make a more reasonable throughput to bandwidth/storage tradeoff
That constraint is perfectly reasonable and rational, not a thumbsuck.
It's neither reasonable or rational. As technology improves, the cost of bandwidth and storage decrease, and latency decreases. Rationally block size and block time should reflect that.
Without some way to squash history, I don’t see how it’s possible to fix this. The bitcoin chain is currently 400gb. If we bumped it up to 10mb blocks we would be looking at several terabytes while still not being anywhere near big enough to handle real transactions.
It does not really matter, as only miners (and large buisnesses accepting bitcoin) would need to run a full node.
All these non-mining nodes have no real effect over decentralization, as they can't counter a 51% attack.
Bitcoin is already way more inefficient than the current financial system. Just compare cost per transaction between Bitcoin and Visa, for example. People seem to think that Bitcoin will somehow replace the entirety of the financial system when it's not even designed to do that and only really handles transactions.