There are lots of nodes loaded in Electrum wallet, so that means all those node runners know users IP, right?
Technically yes, although we don't know which Electrum server actually perform IP/Bitcoin address logging.
And blockchain analyze companies get the data from those node runners, filter it, etc.
Only if those Electrum server is owned by blockchain analysis company or owner of the Electrum server share logged data with blockchain analysis company.
For security purpose, let's assume that every Electrum node logs transaction and Electrum server shares logged data with BCA companies.
Long story short, as I understand, we shouldn't be lazy and mean and should run our node for enhanced security.
But if I use Bitcoin Core wallet and run my own node, then is it still possible for someone to know my IP address?
Theoretically it's possible. But in practice it's very difficult task since ISP or other node don't know whether your node broadcast either your own transaction or someone else transaction.
Aren't transactions processed by all nodes?
Btw there is a thing I want to clarify. So, it's possible for node to know the IP of person who makes transaction but overall this is not something that's automatically logged in the Blockchain, right? If I open node and download all the data, there won't be any logs of IPs but the day I start to run my node, I'll be able to log IPs if someone connects to my node.