I once worked in a factory making upholstery for Detroit Auto Show cars...all GM. Heavy leathers and vinyls and fabrics, indstrial sergers and sewing machines...followed by foam and fabric installation. The pneumatic tool could do 80% of the fasteners (extra were specified for a tightly tailored appearance) and the remainder were done by hand. Even after a summer of doing the same job, the hand installed rings were still the most miserable part of that sweatshop job.

If you don't install covers every day and don't typically use linesman's pliers or similar tools, you'll feel it.

The plier is also maybe just a bit spread-handled for a comfortable grip for me. I'm sure that factors into it, but I do have good grip strength.