Basically all (hardly even an exaggeration!) other cryptocurrencies are attempting to improve upon the throughput issue. Solana is a particularly prominent one with 50k/s
I looked into it and Solana requires "Validator" nodes to be specially blessed by them to get rewards for running their software, so this isn't particularly de-centralized.
I'm interested in how all these other chains deal with people writing tons of junk transactions per second to bloat up the chain.
Having a transaction fee de-incentivizes most people who want to do this
Every junk transaction costs them money
From what I’ve seen they don’t
NANO actually just went through a pretty big spam attack and it crippled the network for awhile, but they supposedly came up with a pretty novel solution in the latest version. I haven't dug into it yet though. But NANO is fee-less, so it is (was?) more prone to these types of attacks. Having a fee increases the cost of a spam attack.
I don't know about other chains, but for ethereum you get money for destroying/freeing up block space. This is how the Chi gas tokens work: they write 0s to the chain when gas is cheap and destroy the blocks when gas is expensive.