They don't.
@8893 is right, my place (soon to be sold next week) is about 35-40 minutes from Lawson's and an hour from Waterbury (Alchemist original location) and maybe another 15 to the new Alchemist spot in Stowe. So I watched this pretty closely, and lived it.
So flashback 5-6 years or so, Treehouse was sold on a farm in the boonies of Monson, MA. Huge lines for maybe 10 cans a person. Trillium was only Fort Point, no tasting, just take out cans and growlers. There was no Foam. No Upper Pass. No Proclamation. No Tilted Barn. No Foley Brothers. And so on. So demand for the Lawson's Sunshine beers was massive and same for Heady and Focal. People followed the Alchemist truck from stop to stop so they could but one 4 pack.
Alchemist saw that model and built a brewery in Stowe. It has a short tasting line and is otherwise just for pickup of cans. Incredible mistake, especially for a place that started as a brew pub. Prohibition Pig, on the old Alchemist site, is a better visit.
Trillium expanded to Canton, then expanded Fort Point, and eventually Fenway. Initially same model, grab cans. But they found the on site drinking was popular and expanded that, even though the facility in Canton kind of sucks for it. Now they are building a new Canton brewery with a restaurant on site.
Treehouse built a massive brewery in Charlton, in the boonies, if less so than Monson. Expected mostly can pick up. At first the taps were always closed. They were wrong, and have now had to reinvent a multimillion dollar brewery twice. Massive indoor and outdoor drinking space now, separated from can pick up. It's really a stunning brewery. I can't imagine there is a nicer one anywhere.
Lawson's partnered with Two Roads to brew Sip and SS. That allowed Lawson's to expand late and they saw what mistakes the others made and built a very nice, small brewery in Waitsfield, with plenty of on site consumption space. Separate area for can pickup, which can open earlier. Smartly done.
But nobody is driving from Maryland and PA and NJ to northern Vermont to get Heady Topper, Sip or Double Sunshine anymore. Not with Other Half, Singlecut, Carton and dozens of breweries making DIPAs and IPAs that are arguably better, and even Trillium and Treehouse are much closer. The on site can volume they expected isn't there anymore, so they need to distribute to use the capacity they built. So far Trillium and Treehouse have avoided that.