It's a rather controversial topic to discuss about. The thing about block interval is that the security of the network is taken into consideration. With a faster block, there is a risk that the propagation of the block within the network is too slow and that miners ends up mining a lot of orphans and causing more forks. Since Satoshi never publicly stated his rationale for the 10 minute block interval, it is widely assumed to be arbitary. Arguably, with better internet connection right now, the block interval can be lowered but there are still quite a few concerns.
No, the network won't be less secure with 5 minute block time. I don't really think so, for example Digibyte has 15 second block time, but it is very secure, proof of work, I have never heard it was hacked, 51 attacked, reversed or forked. The point is not solely the security in my opinion.
How about block orphan rate? It's biggest concern when we're talking about fast block time interval. The security depends on total hashrate and whether there are any bug which allow 51% attack at lower cost (e.g. Verge 51% attack), not block time interval.
Orphan rate for Litecoin at 2½ minute blockspeed is ~2 orphans per day average.
10 minutes is pure overkill.
Moving BTC to a 5 minute blockspeed would literally double it's transaction capacity.
It would also help miners earn double the amount of potential transaction fees.
* Miners need to earn more from transaction fees, if they are to survive the continued rewards drops at the halving. *
But as we know the last thing the Bitcore devs want is to actually improve onchain transaction capacity.
Preferring instead that the Banking 2.0 Scam called LN be the main offchain engine for world wide transactions.
It is the time , that makes the difference , the more time that passes the more secure the chain.
30 minutes in BTC is considered ultra safe
at 10 minute block speed it takes 3 confirmations
at 5 minute block speed it takes 6 confirmations
But either way you are waiting 30 minutes.