There shouldn't be a steel discussion anyway, as both slipjoints and locking folders use all options. But the OP was under the impression that slippies often have 'inferior' steel, and it was followed by specific suggestions for Case CV, GECs and Schrades, which came in 1095. Also, being easy to sharpen was mentioned several times as a benefit, which very few are going to associate with something like the S60V in a Bose or BG-42 in a Britton. But if anyone has to have a patina and pegs touching up an edge on the bottom of a coffee mug as a critical requirement, then they can tell makers like Tomes, Alsdorf, Easler, or dozens of others that they're doing it wrong.
There are slipjoints in super steels with carbon fiber, titanium, and more. There are locking folders with low alloy steels that will rust, including 1095. There are slipjoints with pocket clips and one hand opening. There are locking blades with a nail nick and a sheath. This polarization of us vs them by some posts is empty and baseless.
I have a Ray Kirk folder, hand forged 52100 blade, slipjoint, wood scales. The liners are titanium, the scales attached by torx screws and stabilized, so has a lot of 'plastic' in the mix. I have an Enzo folder, natural birch scales, no lock, nail nick to open. Blade is S30V and I removed the shiny deep carry pocket clip. Al Mar SERE 3003A. Nail nick, stainless bolsters, brass liners, sheath carry. Locks, blade is a Japanese stainless, it's pretty damn large and 'tactical'.
I think M4 wins most of the cutting competitions, unless things have changed the last couple years. That's a very alloyed steel with a 12% carbide volume. Not really closer to carbon steel than S30V.