I am talking about the wallets for altcoins, we only have very few in numbers which are considered to be a secured wallet to store altcoins such as MEW, Unstoppable wallet but many others were closed source or it has to be hardware wallet so just looking to find the reasons why developers are not interested in building a wallet like electrum for altcoins?
I'm not quite following your question. Are you suggesting that we don't have good wallet apps for altcoins? I know Anchor for Antelope (Eos, Telos, Wax...), Metamask for EVM (Bsc, Thorchain, Polygon, Celo...), and Phantom and Safepal... I think they're pretty secure and reliable. Only a few wallets are closed-source like TrustWallet, but even they've had a good track record for years.
Electrum is a good wallet for BTC, but I don't see my friends using it much. They prefer multichain crypto wallets to manage assets across different blockchains.