Bungie usually tends to tie high-stat armour to challenging PvE activities but Beyond Light brings more options to Destiny 2. You will need to be on the lookout though.
Weekly challenges in Destiny 2 can provide useful rewards, especially during the process of boosting your Power level but Beyond Light features some important changes.
First of all, obtaining items from the weekly challenges that require you to complete a number of bounties with Zavala, Shaxx or Drifter will no longer be a way to earn Pinnacle rewards for reaching the hard cap. While this may sound disappointing, it will benefit the larger portion of Destiny 2 player base since they can earn full sets of useful armour now.
Weekly challenges will award players the Prime Activity Engram. It will contain a piece of armour and you can do this up to five times since all five of armour slots can be filled from with challenge loot. Each time you earn one, the armour piece you earn will be removed from the engram's loot pool so you don't get duplicates.
With all of this in mind, make sure you don't let your brain go on autopilot and accidentally delete an armour piece that could be highly useful if you decide to masterwork it.
After the full set of high-stat armour has been obtained, the engrams will start dropping low-stat pieces so you won't be able to just farm a ton of 60+ stat goodies by completing bounties for the trio.