SGI is, or was, very evangelical, keen to prosthelytize. In the US, the various immigrant communities, by the fact that they provide service only in Thai or Vietnamese or what have you, might be prothelytizing, but it would be invisible to me since I don't speak Thai.
Ancient Buddhism was not content to wait for people to just magically show up and learn the Dharma,
"The Sangha had grown to 60 in number ..
and Buddha sent them out in all directions to travel
alone and teach the Dharma. "
There is a better quote for this, but I can't find it.
In China, Thailand, India for a while, Japan, it was a state supported religion. As such, it has a massive advantage in getting adherents. In fact, in Japan, the government would just assign you to the county Buddhist temple.
And finally, when people talk about growing membership, all they can think about are Jehovah Witnesses at the door with Watchtower trying to do essentially door to door personal sales in a world where nothing is sold that way anymore. Marketing is done with online media, writing books and getting them on book store shelves, getting the military to recognize your religion so it can participate in the chaplain program. All of that is a million times more effective at getting more members than tacky, pushy person to person sales.
In the Brahma Net Sutra, there are several precepts obliging precept takers to teach the dharma and to teach it well, which as a side effect may result in more self-identifying Buddhists.
So Buddhist doesn't lack in prothylthizing, what it lacks (other than the example of SGI) is a marketing campaign involving tacking person to person sales. Just about everyone else is working on "growing membership" but by other means.
(This contrasts to what a lot of atheist think-- that no one should teach anyone, not even children, anything about any religion unless that person spontaneously and enthusiastically asks for it)