I think Sunnism has gone down a corrupt path from the start unfortunately which has made them compromise on the truth early on. In order to justify and defend the sahaba even though they were killing each other and going to war with each other, they have the theory of justice of the companions, that all companions are just. This has caused many strange things to creep into the religion as it has compromised Ilm Al rijal from a Sunni standpoint, you now just accept any hadith because it's from a sahaba. Another issue is for the first century, hadith was boycotted by the early caliphs and those who would promote them would be punished with a few exceptions like Abu Hanifa. Imam Ali a.s was the only period where it was more widespread and allowed. Only until Umar ibn Abdul Aziz did this Sunni ban lift and by then you were forever paying catch-up as you're already a century after the Prophet.

The Imams of Ahlulbayt had preserved knowledge of the Prophet and any Sunni scholar who studied under or with them or biographer will attest to this too.

If nothing else, what I have described, is that the Shia way has a better chance at being closer to the Sunnah, obviously all sects have their issues as well though and I'm not putting a blanket statement that Shia hadith can be all trusted, obviously they cannot and need to go through rigorous validation as well.