It's just so much more cost effective. You get exactly who you want without extras to unload later, and no shipping fees. I also try to favor shopping at local stores rather than ordering. Even the big chains provide jobs for local people, versus random warehouses who knows where. That, and mail order can be extremely inconvenient if you work 9-5 hours. Couriers are unforgiving sometimes.
Sadly, with the pandemic, it's really not a viable option. I ended up grabbing random fistfuls and did manage to get the whole set in two goes, at about 1/3 the cost of a box. I've a disproportionate number of spares this time, but I still came out ahead.