Will it be easier for hackers and thieves as more wallets get used?

So in future when more people are using crypto, let’s round the population up to 10 billion…

And let’s say each person has 10 separate seed phrases (I know they won’t though), so we have 100 billion non zero balance seed phrases.

What would the odds be of someone being able to guess or brute force a seed phrase that leads to an active wallet?

I’m just trying to figure out how secure it is to have all your funds in the 1 wallet, and if it’s better to separate funds across multiple wallets.

I know when you include passphrase wallets, it essentially becomes an infinite amount of wallets, but let’s assume passphrase wallets don’t exist and base it just on seed phrase wallets.