EPS is single-user: you provide a list of xpubs/descriptors at startup and it only indexes those. Storage requirement is minimal (a few hundred MB beyond the Bitcoin Core chain itself). Electrs and Fulcrum, in contrast, build a full address index over the entire chain and can serve any wallet, but require 100GB+ extra storage.
For personal use, EPS is the right choice. For powering many wallets, choose Electrs or Fulcrum.