Why would Monero be much easier to use than Zcash? I'd say XMR is harder to understand than ZEC because of the way it's designed. It uses three keys instead of two used by coins like Zcash and the others (Bitcoin, Ethereum, etc). ZEC only has shielded addresses, whereas Monero has a public key/address, a spend key, and a view key. If you want someone else to view your transaction history, you'd need to share your view key to do that. Using only the public key won't suffice.

It takes quite a bit of understanding to get your way through the XMR blockchain. And it's even worse with Mimblewimble coins such as Grin, BEAM, and Litecoin (yes, Litecoin added said privacy feature some time ago). I think that's one of the reasons why privacy coins are very unpopular. At least, there are plenty of options to choose from. As long as R&D for privacy/anonymity continues, we should have nothing to worry about.