What I’ve noticed in new construction, is that they commonly have Satco light bulbs installed when it is built, rather than GE, Sylvania, or Philips, even though some use faux Westinghouse, and in some cases the actual big three. I just toured a new construction this week and all the bulbs in the house were SATCO LED’s. All of them, and even in the 2000s I often saw videos of people removing satco bulbs when burned out (satco isn’t even available at all stores, most big box stores don’t even carry satco), so those were likely majorly installed by builders. I also went to a house where I saw satco bulbs (and I’ve seen some arc), and the house was full of them, the bathroom lights had clear bulbs and the bare bulb light and flushmounts I believe had the frosted version. Also, when I watch Lex’s dirty maintenance show, and he changes a bulb, I notice that some look like satco lamps, especially IF A19’s and candelabra bulbs.

Has anyone else been noticing this? Why is satco of all companies likely the most common light bulb choice for builders. Satco never even made bulbs, they only distribute bulbs and another company makes them for Satco. Whatever company who makes satco bulbs makes a lot of bulbs for different companies as well, like Halco and some other ones. A lot of the other “60W 130V 2500 hour” incandescent bulbs for example were made by the same company who makes the satco ones, with the same “LR58060” on the base. It also seems like many new construction pre-2020 were built with incandescents from satco or whatever and they put in the 130V ones for some reason with the C-9 filament to avoid the ban.

In my experience, I do recall seeing Satco lamps being sold at some ACE Hardware stores in the USA.

They will purchase in bulk and get good deals in bulk.  The dealer I deal with here in Colorado uses Satco and Ledvance (Sylvania) I've had good luck with Satco thus far.

I haven’t noticed that, but I did find a 6 way floor lamp from 2020 and all four bulbs were Satco incandescents which I thought was odd because I don’t know anyone that sells that brand here.

Satco is commonly found in distributor networks. Ferguson and Build, Inc. both carry Satco products. I have about 45 cases of miscellaneous Satco LEDs, from A19 to PAR38. They are "Builder's Choice" as they are cheap enough, look decent, and often last their rated lifetime. The only consumer retail establishment I know of that carries their product lines is an Ace Hardware about 3mi away from my home.