The R-7 rocket was originally designed as an ICBM. When America unexpectedly invites you to a friendly game of global thermonuclear war, it’s not acceptable to say “Not today thank you, it’s cold outside.” So they built a rocket with enough margins that it could launch in all weather conditions.
Ultimately the R-7 was a military failure since it required a day of prep on the pad before launch (compare with one month for the shuttle). So it was replaced in its ICBM duties with instant-launch rockets like the R-36 (known to the West as “Satan”).
The shuttle had so many moving parts/components that it was frail. It required ideal weather conditions. Even a slight wind would cause delays and God help you if it drizzled or a little rain — grounded for a week.The fact Soyuz launch regardless of weather conditions tells of unglamorous, pragmatic Soviet approach is the clear winner when it comes to space programs. As demonstrated with their ability constantly and reliably loft humans to LEO which Americans have lost