In my opinion, crypto-sector is competing with the traditional financial sector. So, the growing interest in cryptocurrencies weakens the interest in the traditional financial sector.
I don't think the legacy financial sector is getting weaker. Exchanges need bank accounts, providers of crypto related debit cards need bank accounts, payment processors need bank accounts, etc.
That to me doesn't seem like the legacy financial sector getting weaker at all. Crypto depends on banks accounts more so than people are comfortable admitting. Maybe this will change one day, but that day is faaaaar away.
I'm not sure if you have been following the progress the banking sector has been going through, but I can pay for things instantly, for free and that 24/7. That's extremely bullish for banks, less so for crypto.