Electrum they dont need very long to download the full blockchain?
As our friend explained, you won't have to download and store the full Bitcoin blockchain on your device with Electrum wallet that is SPV.
Looks like you misunderstood the brother's point, Electrum is a lightweight wallet, it doesn't require downloading the whole data, So don't be afraid of the storage and hardware resources.
You can connect your Electrum wallet to servers and use it immediately. No need to wait for days, hours or few minutes to sync your wallet like Bitcoin Core.
Electrum uses
Simple Payment Verification technique.
Simple Payment Verification (SPV) is a technique described in Satoshi Nakamoto’s paper. SPV allows a lightweight client to verify that a transaction is included in the Bitcoin blockchain, without downloading the entire blockchain. The SPV client only needs download the block headers, which are much smaller than the full blocks. To verify that a transaction is in a block, a SPV client requests a proof of inclusion, in the form of a Merkle branch.
SPV clients offer more security than web wallets, because they do not need to trust the servers with the information they send.
Reference:
Bitcoin: A peer-to-peer Electronic Cash System