This... I wonder why most of the apps that are tied to the governments ^{[not just El Salvador]} have limited or rather unreasonably low server capacities?

I believe it's a custodial wallet.

I'm not an iOS user, but here's the link: Chivo Wallet
^{- At the moment, it's #5 in the Finance category, but earlier in the day it "was #1".}

And here's where it gets tricky:

• Quote from: https://www.theblockcrypto.com/post/116870/el-salvadors-chivo-bitcoin-wallet-struggles-to-reach-liftoff-on-launch-day
  Some users reported issues sending the funds credited to their accounts. It appears that the initial $30 can only be sent to other Chivo users and merchants rather than to other wallets outside the Chivo ecosystem. Some have taken to Twitter to post possible workarounds to allow users to withdraw the $30. They claim the funds must pass through a few Chivo-to-Chivo transactions before they're unlocked for withdrawal.
  ~Snipped~
  Matt Ahlborg, head of research at Bitrefill, tweeted his test of the Chivo functionality. He found the $30 in BTC could be sent off-chain after three to five Chivo-to-Chivo transactions and Lightning payments can be sent to and from the wallets.