Comment by popeathlete

No offense, but this largely reads to me like "I don't wanna use Linux because I wanna use Mac". If you want to move to a different system, you can't expect to get the same thing. Really, the only complaints I can agree with now are 2 and 3, the rest is just invalid. You've got kdeconnect gsconnect nextcloud keepassxc many, many configurable mail clients, especially the beatiful, integrated kmail and their whole PIM suite, Okular has all three features you mentioned. You just have to put in a bit of work, it's a DIY system after all.