> Market capitalization is fairly meaningless
I agree with that. Marketcap + Volume can still be compared to other assets. Determining how much is wash trading versus something else is unfalsifiable in crypto, the nature of transactions cannot be determined with only a limited analysis available on centralized and decentralized exchanges. But not the unlit markets, or the nature of transactional demand.
Compared to currencies, crypto assets function similarly with M0 and M1 being the tiny liquid cash thats actually moving and M2 and M3 being the illiquid much larger aspect of the currency. It requires a completely new standard to criticize crypto assets based on the exact same observation.
Compared to securities and commodities, crypto's much lower marketcap and high volume (see my first paragraph for why I don't mind the volume) is a great proportion. So, in your two-fold point, there still must be some standard for relative comparison, what would your alternative be? I choose market capitalization, understanding that a significant portion of it is relevant to value transferred from other financial ecosystems directly for exchange of the crypto asset, supporting its valuation much better than a low float asset we make in a spreadsheet.
> Liquidity is very much lacking in the crypto world
Its pretty decent. The unlit markets are bigger than the lit ones. Any OTC desk can corroborate that. Someone trying to swap in and out can use both the lit markets and the darkpools. For the size of the market, crypto's liquidity again relatively great. Of course, I see how paradoxical it is to mention "size" of the market, again, but you're not leaving me with much in the English language to work with for relative comparison. Although its totally fine for me. The market works for me.
> Stable coins were developed not in a vacuum, but precisely because liquidity was so lacking.
Although I disagree with the liquidity issue, I don't ... care about this distinction? I consider stablecoins to fulfill a market need and are crypto assets, the market noticed and used them, some of the biggest ones are currently surrogates of fiat assets. Liquidity begets liquidity, so anything that attracts liquidity is a net good to me. I don't consider the crypto space to "need" them, I consider the market to have chosen the thing that fulfilled a need, and that grows/grew the market.