This might sound ridiculous but there is a chance market cap isn't truly increasing.
What we may be seeing is a shift of market cap from fiat to crypto currencies. Crypto's rising market cap might better be described as a paradigm shift whereby wealth is shifting from traditional fiat currencies and the economies they represent. If the world's markets and economies are dwindling and growing less wealthy over time, that might be explained by the world's wealth being shifted into bitcoin instead.
What we may be seeing is bitcoin gaining value as people abandon the world's markets and fiat currencies and choose to pour their wealth into bitcoin/crypto, instead.
Ahum, that still means the Total Marketcap of Crypto is increasing...
The market cap of a lot of things are increasing due to inflation, including the crypto market. Even if cryptocurrencies don't gain value, their dollar equivalent will keep growing due to the USD's inflation rate being higher than many cryptocurrency's.
The total world Market cap is directly related to the amount of value (Items, services, etc.) connected to it, which is growing as well.
So now I wonder what point you're trying to make..
The cryptocurrency market is to concentrate in itself inflationary dollars. It will be endless. But agree with me that it is better to have savings in cryptocurrency that attracts impaired dollars than to have a Bank account and every year lose the purchasing power of their savings in Fiat.