Why you say can't and shouldn't be disputed. Still the question remains why a lot of coins claim to have low fees when there is literally no trading volume (no liquidity) at all. Transaction fees might be low, but you just can't use the coin to transfer funds as you can't get out of it anymore. That's why I think that there won't be tens of thousands of functional currencies in the future. It makes more sense for all of us to converge to a couple of them and thereby reduce all kinds of premiums, like the liquidity premium.
Consolidation down to a few coins is certainly a possibility. However, I think there is also the case to be made for a larger number of coins that, by supporting atomic swaps, be it through second-layer solutions like LN or via DEXs, provide increased resiliency against attack and centralization efforts by supporting multiple simultaneous network paths. For POS coins, the energy requirements can be mitigated by having the majority of coins use AuxPOW.
The other interesting benefit to having multiple tokens/coins is that they can provide unique utility, DGB's password manager feature being an example. Many purpose built chains that do one or two things well would be better than having a kitchen sink/jack-of-all-trades, master-of-none approach. I do agree that tokens/coins that merely tweak rewards, block-timings, etc. will cease to have value.
