We know that Lightning network is already there but it hasn't been able to take off yet, not many are using it. Why still bitcoin old network is preferred over LN? Its because we still dont trust this new concept.
Because there are really few merchants accepting Lightning payments. The UX for actually using Lightning is also difficult for the average user. Although there are Lightning custodial wallets, like BlueWallet for IOS, which is easy for newbies.
On the topic of solving the Blockchain Trilemma, Lightning itself might not solve it, but I believe developing Bitcoin as a layered protocol is the right path.