An increase of 0.51% doesn't mean supply is increasing much but it also means that there is no reduction in huge amount of ethereums that are in circulation. There are 120 million etherum coins in circulation and this annual increase will kill one of core objectives of switching to PoS which is to reduce the number of Ethereum coins in circulation.
It depends on demand. If there is an increasing demand, this increase means nothing. Also, 120 million Ethereum coins are compared to a daily trading volume of around 9 million.
Which means even if total supply doesn't grow at all and stay at 0% its already bad enough.
The percentage is still lower than Bitcoin, but the lack of demand is the main problem.