The business is in selling replacement cartridges, not razors,
since I replaced my 15 years old Gillette Mach3 with a Schick, I am now forced to buy Schick cartridges, likely for a long time
if someone else will purchase for me, the same applies, blades are not interchangeable between brands, I can't use Gillette cartridges on my new razor, I might buy Gillette disposables, but that is not desirable (lower quality product) or maybe purchase a new razor, which happens once in a couple decades
so Gillette is quite vulnerable to a boycott
since I replaced my 15 years old Gillette Mach3 with a Schick, I am now forced to buy Schick cartridges, likely for a long time
if someone else will purchase for me, the same applies, blades are not interchangeable between brands, I can't use Gillette cartridges on my new razor, I might buy Gillette disposables, but that is not desirable (lower quality product) or maybe purchase a new razor, which happens once in a couple decades
so Gillette is quite vulnerable to a boycott