I don't know if they still are, but it'd be pretty damn hard to create anything cool out of a segwit address unless maybe it starts with a 3.
It's possible to generate bech32 vanity addresses and I don't think that's more difficult than generating a legacy vanity address.
The only problem with a segwit address is that it can't include 1, b , i and o and you can't have a vanity address containing those characters.
On a related note, if you import a Mycelium seed phrase into Electrum, you have to choose BIP38 and then you get a choice of address types, legacy included.
That's not limited to Mycelium's seed phrase. Any BIP39 seed phrase can be used for generating different types of addresses.