How can you attribute these problems to Linux? The "Modern Standby" relies on proprietary drivers and closed specifications, which are only shared with Windows developers under an NDA. Linux community has to reverse engineer the hardware to make it work. You should not expect that it will be successful for "a wide variety of laptops" for free.
> On the contrary, it's often the people who say they have no problems who have the real exotic hardware
Yes, but it does not matter whether you have "exotic" or "not exotic" hardware at all. What matters is whether it was designed to work with Linux.
P.S. Standby and wake-up work 100% of the time on my Librem 15, which was designed for Linux.