Are cryptocurrencies ready to handle large number of transactions?

[Georgi Guninski]

Are cryptocurrencies ready to handle large number of transactions?

Say if the database is 1000TB or more?

Doesn't handling large number of transactions contradict
decentralization?

Several days ago the BTC blockchain was about 150GB.

Heard complains that BTC fees are rather large and transactions are
currently slow.

With growing popularity the database size will increase.