Once again I did not vote in this TPU poll since there is no correct poll option (I do both).
Sometimes I use the regular online retailers: Amazon, Newegg, Best Buy, Apple.com, etc. Sometimes I use bricks-and-mortar retailers: Apple retail stores, a mom-and-pop PC store, retail Best Buy stores, the now defunct Frys Electronics, etc.
There are certain items that I only buy in physical stores. 3.5" HDDs are one and I grab an external enclosure at the same time. Sometimes I've purchased SSDs at bricks-and-mortar.
The bricks-and-mortar electronics stores in Japan are awesome: Bic, Yodobashi, Donqui and all of those miscellaneous retailers in Akihabara, etc. It's worth walking around some of these stores, there are tons of products that aren't marketed in the USA or Europe. Hell, there are things that I've imagined that make total sense once I've seen them.
One thing for sure, iPhone cases in Japan blow doors on the offerings here in the USA, especially on price. I typically buy thin clear cases around 1000 ¥ (about $6.50). Equivalent cases in the USA are around $20+, stupidly overpriced. There are tons of little things like cables, chargers, peripherals, and more where buying in Japan is way better than Big A, FleaBay or AliExpress.
Hell, I have no problem buying miscellaneous tech goodies at 100 ¥ stores (dollar stores) like Daiso in Japan.
Japan is the place to buy things for a travel kit. Those guys know how to make things small and compact. My bag is properly kitted out with a bunch of this stuff.
There are other things I'll only buy in Japanese bricks-and-mortar stores these days, like rechargeable AA and AAA batteries. I buy Panasonic rechargeables in Japan which are basically Eneloops without the Eneloop branding and pricing.
I have also never paid full retail for a copy of Windows. The local mom-and-pop PC store has sold OEM copies for the past 25+ years if you buy a primary PC component (CPU, GPU, power supply, motherboard, case, drive, etc.). These days I'll just buy a bulk key online but I continue to buy stuff from the mom-and-pop store.
Likewise home theater equipment has been a mix of both online and bricks-and-mortar. When I was shopping for an LG C2 55" OLED television, I also checked out a local television retailer who ended up being the lowest price of anyone. They even had a deal to slash $100 if I brought in an old TV set (which I did, a crummy little 21" television gathering dust). A/V receivers, speakers, etc. Half online, half physical retail.
Even for big ticket items like computers and phones, it's a pretty even mix of online and bricks-and-mortar.
One thing I noticed is that sometimes a bricks-and-mortar store will still stock a discontinued item after online availability has evaporated. Most recently I picked up a discounted EOL Arctic Liquid Freezer II 120mm AIO after general availability at online stores had dried up and the only items available online were from independent sellers engaged in heavy price gouging. And yet there was one sitting on the shelf of my favorite local B&M store in the color I wanted.
If you do all of your tech buying online, you are certainly going to limit product selection and availability. And sometimes pricing in certain cases.