Samsung sure better than Huawei in term of firmware update on phone. They won't update phone after excess 2 years.

Yes good example to my previous P9 Plus & my wife S7 edge. My wife bought her phone earlier than me and still update till March 2019 before she upgraded to P30 Pro. My P9 Plus already stop any update since Aug 2018. No more firmware support. Actually my P9 Plus still working good but just no firmware update. I changed to Mate 20 Pro then Mate 20x due to want better camera spec.

Most of the manufacturer will stop provides updates after certain timeframe. I owned both brand of phones, Samsung and Huawei, like what the previous post, Samsung is slightly better than Huawei . Alternative if you want constant up-to-date firmware/ software, you need to get a Google Pixel phone

Yes but it is not a MUST if already fully utilize the phone after two years.

Well updates all depend on the phone model & spec and also Android version. 2 years timeframe is good enough.

I think the same but not sure in future. Policy can be changed anytime.

Yup , Pixel is quite expensive due to those importer that brings it in also want to earn profit, nevertheless Pixel is for those who want pure Android experience. As for those top brand, their hardware spec is much better than Pixel. Each of the company have their own advantages and disadvantages.

In the end, it is up to us as a consumer to buy the phone that we feel suits own needs and requirement

Another brand to look for is ONEPLUS as their OxgenOS is near android like

I'm not sure on their updates on the recent ONEPLUS models but my previous model, which is the 1st ONEPLUS is regular. Anyway my next phone will most likely be from ONE PLUS