It seems an unfortunate consequence of the forces involved in making vaccum sealed preserves. If the force necessary to open the jars were higher than the average male grip strength, then I predict we would have jar-opener devices as standard in kitchens, like we have can-openers or bottle openers. In fact, the old style cork screw for opening cork bottles is probably requiring the higher side of male strength, which explains why we have the newstyle bottle openers with the cog wheels and arms as a force multiplier.
In short, blame the patriarchy for normalising a lack of jar-openers in kitchens, but don’t blame it for the force required to open a jar.
This feels like the wrong read. Guys who do well here are not necessarily “making advances” or “playing the numbers game”. I think they’re probably just talking to them and getting to know them a bit like a normal person and at some point they may show a sign that they are interested (or become interested! I think you’re still working on the premise that women have decided if you are attractive right at the start when they first see you, and then are waiting to reveal this later on, when in fact it can happen minutes, hours, days later).
The “numbers game” guys aren’t normally showing genuine interest or really treating women like people at all. They’re just shooting their shot and then leaving when it doesn’t work.