Yes, but there's an alternative now that requires negligible practice and totally negates the effort and concentration needed. If one thing requires tremendous amounts of training and practice and the other offers immediate proficiency to amateurs one is, by definition, more convenient. You can decide it's speed all you want, that does nothing to make it true.
Shrug. This could be a matter than I'm older than you and have had traditional knives in my hands longer than you. But for the life of me, I don't find a noticeable difference in effort and concentration on opening.
I do notice a HUGE difference in the amount of concentration need to one hand close modern liner/frame/mid locks (and traditional lock backs) compared to slip joints and friction folders. The former can't be one hand closed without putting my fingers in harms way of an active blade while the latter can.
I agree with you completely that modern knives are much easier for novices to learn. That's an excellent point I hadn't considered and you are spot on in pointing that out.
I can only add that I've found some things in life that are easy to learn, some things that are always hard, and some things that are hard to learn but easy to do once learned.
Putting a workable sharp edge on a basic steel using a whetstone is hard to learn. Just look at the knives in your friends kitchen drawers or inspect the edges of 99% of SAKs in circulation. But, once learned, it's very easy and it would be wrong to say that just because it takes some practice that it's hard (or impossible).
[Priming white gas stoves and using down-tube shifters on road bikes are other things that are hard to learn but easy to do, once learned.]
Last though on the word "convenient"... I find it convenient to have a knife that I can deploy in just about any setting without upsetting people. The large Sodbuster and the Opinels are convenient in this way whereas most traditional lock backs (very much including the Buck 110) and pretty much all moderns I've handled tend to scare a few people.
In the end, I think convenience is pretty context driven. For general EDC use, I find knives like the Sodbuster and Opinel much more convenient overall. They are easily (and I do mean easily) opened and closed one handed, which is very useful when working around the property and the shop, they carry better than a pocket clipped modern for me in a rear pocket and they can be used without scaring people as easily as moderns (and big traditional lockbacks) do.