and if that kind of privacy is important to you then splitting makes sense otherwise i can't think of any reason.
Security would be a reason to split them. 5 BTC in one address, be that a paper wallet or an airgapped device, is a single point of failure or a single point of theft for your entire holdings. I would split it in to at least a couple of parts, spread across different paper wallets or airgapped devices.
Say in 5 years I want to send someone 0.05 BTC wouldn't they see I have 5 BTC (now 4.95).
Yes. But lets say right now you split the 5 BTC in to 4x1 and 20x0.05 like you suggest. In 5 years' time when you spend 0.05 BTC, the receiver only has to go back a single transaction to see the 0.05 was split from 5 BTC and could make a reasonable conclusion from that. At some point along the line you are going to want to mix your coins to obfuscate how much you are holding.