Also, when using Electrum wallet to create your key, you are trusting their Entropy, which it can be VERY secure and everything. But i feel safer trusting my own entropy.
Electrum doesn't collect any data whether seeds, privkeys or whatever and to ensure that you can generate the seeds on a completely offline device that gives the satisfaction of the seeds generated doesn't transmit anywhere.
But if you're technically sound and can make your own privkeys then it's good but more often the randomness of the human brain fell short in every day.
And you can completely trust the entropy of electrum seeds or BiP39 cause it's not practically possible for anyone to brute force in million years.