Separating the seed phrase and storing it in two different places increases security but also brings more risk to our bitcoins. If we thought that storing the private key or seed phrase in 1 place wouldn't be secure enough and someone might find out. Then storing 2 places will not be more effective because, in the first place, we have chosen an unsafe storage place. I think this will only complicate things, not bring much effect. Instead, find the safest place and only we know about it, the storage will be safer and more convenient for us.
Fair point, people, when thinking of security, tend to only focus on possibility of someone hacking their keys over the internet, but that's only one of many vulnerabilities. Losing keys stored in a physical location also needs to be considered (be it theft, fire/water damage or simply forgetting when you put them) - and the more physical location there are - the greater the risk.
But perhaps OP meant to split the phrase and keep it separately in an electronic version, i.e. as an encrypted file saved on 2 separate email accounts etc.
Split the seed phrase and save it on 2 email accounts or is it safer to save it on 2 or 3 online storage services? I've heard of this method but I never believed in hosting on online platforms, even though it sounds like a pretty good way. But the inconvenience here is that you also need to remember 2 or more email passwords, and preserving 2 email passwords is like storing seed Phrases in 2 places.
To be fair, every method has its pros and cons, which may be safe for you but not necessarily safe for others. So let's keep it in the way that we feel is safest.