Altcoins might be faster, but at the expense of less security. Have a look at https://github.com/lukechilds/howmanyconfs.com. Unfortunately the site itself has been down for a couple of months, but you can still see screenshots on the github. Even the fastest altcoins are several times slower than bitcoin to reach the same level of security, but the majority are closer to 100x slower or even more. There are also plenty of altcoins, including some major ones, which have been successfully 51% attacked.

Using altcoins has other problems too. I either have to plan all my purchases in advance so I can buy them as needed, or buy them in bulk and then slowly lose value on them since most of them just depreciate in relation to bitcoin. Much rather just use Lightning.