I do understand the underlying encoding procedure is same but the words are changed, and what if we remove all the words from BIP39 list and use the remaining ones to create a seed phrase for electrum, it will use the same encryption method to create the seed phrase but it will be more safer than before, or I am missing something here.
Seriously, does it really matter if something takes 10^3*10^12+3 or 10^3*10^33+3 years to bruteforce?
By the way, Electrum creates 132 bits of entrophy, 11 bits of entropy per word (12 words). If you increase the number of words in wordlist, like I offered and o_e_l_e_o demonstrated, the number of bits of entropy per word will increase and the number of words will decrease, like he generated 8 words instead of 12 words but his number of bits of entropy per word increased from traditional number 11 to 18.83.
Just read this line:
The math is quite interesting, if you want to work it out. Given a word list of 466k, then each word can encode log2(466,000) = 18.83 bits of entropy. For a 132 bit seed phrase, this needs 132/18.83 = 7.01 words, which has to be rounded up to 8. If you used a wordlist of 474,861 words, then you could generate a 7 word seed phrase for 132 bits.
So, this is a little trick and that's why opened a topic. People think that 2048 words are not enough and their public availability makes them a victim of hackers. Now, what about all the words that exists in English language? Sounds cool, right? Only some words from half a million words to generate your bitcoin wallet seed phrase. But in reality, if entropy is 132 bits, you will get 8 words instead of 12 words. Instead of increasing number of words, one should increase number of entropies and move from 128 bits to 256 but reality is that simply there is no reason. People are paranoid and are looking for false sense of increased security when there is absolutely zero danger. It's like living in New Zealand and collecting weapons to protect yourself from Dinosaurs attack. There are no dinosaurs, you don't need a weapon.