Wouldn't say that the exynos chips are inferior and Samsung put out software Updates monthly
If you read a few anandtech articles, the exynos chips do exhibit poorer performance, and poorer battery life. It was the case with the S9, where in the S9 series the gap was enough for them to only recommend the snapdragon version. Gotta wait and see for a more in depth review of the exynos 9820 vs SD855, however preliminary tests show that the 9820 is, performance wise, slightly better than the SD845.
Regarding the updates, it's a constant criticism of samsung, that they're really slow with a lot of their updates, especially major versions. With that said, my first foray into smartphones was with a SGS1, and it took forever for updates to come when it seriously needed them. With that said, I also had the problem of a carrier branded device. I know better now, but it was early days then. Don't know what it's like now, but I constantly see that criticism, so presume that it's ongoing.