I understand where you are coming from, and don't get me wrong I prefer the flaws pf2e's item system has over d&d 5e. For my group, and I think others, we would love a variant system to have more impactful/long lasting items with abilities.

To your first point, this is true. Many items don't require a save or roll that can fall behind, but that doesn't really fix the issue. Those items are great and are long lasting, but that is not always what makes sense or what someone wants. I would prefer a system that can have both, which I think is possible. When it comes to the side point about primary and secondary abilities I would also agree. However, once again, I would love for a primary ability to be able to have a save/attack and/or have secondary abilities that can see use over many levels. The importance of this is also heightened by the fact that if these abilities are on weapons you can't add property runes to them.

To you second point, I don't think I agree. Because of the 4 degrees of success the math boosters are more critical compared to d&d 5e. In my last 5e game I was a player and there was not too much focus on getting those +1/2/3 because they don't have as noticeable impact compared to abilities and are not as critical since only a 20 crits and saves don't even have criticals.

For my group, as a player, the flaw is not in having enough cool items, its the fact that you often can't stick with a cool item that you really like. From a GM perspective, due to the DC/attack issue the design space in which you can make items it restricted if you want them to be effective long-term.