Whoa... maybe it’s the jenky touchwiz software Samsung bundles on galaxies (if that’s still the case?). Try installing the default google keyboard and setting it as default. Back when I used android, the Google keyboard swipe capability was solid, this was on an LG G6 with some debloated vanilla android rom.
Although I have to say, moving back to iOS has been pretty amazing. Swiping on the normal iOS keyboard allowed me to type this entire message from bed with one hand... barely any autocorrect kicked in...
Different software keyboards definitely have different swiping requirements. I've found that Samsung swiping keyboards need sharper angles at direction changes to help with recognition. Other swiping keyboards are more okay with smooth continuous curves.
Although I have to say, moving back to iOS has been pretty amazing. Swiping on the normal iOS keyboard allowed me to type this entire message from bed with one hand... barely any autocorrect kicked in...