Commercial account will always keep local parts stores open to some extent. People will always need cars fixed and stores will always need parts same day.
As for parts counter guys, its a joke these days. I had the store manager at a local Autozone (yes, the top dog there) try his best to convince me that if I did not buy platinum plugs for a 98 Rav 4 that it will likely cause permanent engine damage. Thats direct quote.
I think a lot of the problem likes int heir HR and hiring methods. They hire any bum off the street even if they have zero automotive experience so they can pay McDonalds wages and keep their margins high. I have seen this at AZ, Advanced, and Murray's around town. The only places you can seem to find good advice and actual help are the smaller non-chain parts stores.
I found this out first hand-I worked part time for AZ when I was 19, was offered a full time manager role in 4 months, and was the store manager 5 months after. I was the youngest store manager in the district by a mile. My store did great because we had a legitimate repeat customer base that came seeking our opinion/expertise. But, after seeing basically a slap in the face of a raise the next year, I re-evaluated my position and the company. I found out that if I stuck it out for 10-15 years, and did exceptionally well, I may be able to be a Regional Manager and make 60-70k (mind you, there was about 60 people ahead of me for that gig). I resigned, and made more the next year Bartending 2 days a week than I did as the freaking Store manager.
Long story short, Amazon is not the reason big box part stores are dying, they are. They are set in their ways- and the guys at the top only look at the metrics-the numbers, and have ZERO idea what is actually happening in there stores.