That doesn't make a difference though? Not using IRC limits who you can reach. In some projects, all the interesting people are easily reachable through IRC (and less reachable through other channels).
Of course there are other projects where all the interesting people are reachable through matrix or gitter or zulip or slack, and if you're interacting with those projects, IRC won't do much to help you. That doesn't mean "not using IRC limits who you can reach" is false; it just means you may not have an interest of interacting with the people who you can't reach without IRC.
That doesn't make a difference though? Not using IRC limits who you can reach. In some projects, all the interesting people are easily reachable through IRC (and less reachable through other channels).
Of course there are other projects where all the interesting people are reachable through matrix or gitter or zulip or slack, and if you're interacting with those projects, IRC won't do much to help you. That doesn't mean "not using IRC limits who you can reach" is false; it just means you may not have an interest of interacting with the people who you can't reach without IRC.