In Destiny 2 it doesn’t make sense to collect and hoard engrams.
Hoarding engrams was a popular pastime in Destiny 1. There, you could collect as many as space allowed and later have them decrypted by the Cryptarch. For example, exotic engrams were saved for high light levels or upcoming content updates.
In Destiny 2, this tactic is no longer possible, as Bungie fundamentally restructured the logic of engrams.
Normal Engrams – from common to rare
Engrams that you find in the game world are instantly decrypted and added to your inventory – no more annoying “flying to the Tower” to visit Rahool. Engrams of the rarities white, green, and blue are automatically decrypted upon discovery.

The missing detour to the Tower has its price – you cannot “save” engrams for later. This shouldn’t be a problem, as you won’t be able to do anything with the white, green, and blue stuff anyway after a certain point.
Valuable Engrams – legendary and exotic
In addition to the aforementioned engrams, you can also find legendary (purple) and exotic (yellow) engrams. These contain the best gear, and everyone is after them. These engrams are not automatically decrypted immediately; you need to fly to the Farm or the Tower for this.

In particular, exotic engrams were often hoarded in Destiny 1 to maximize light level (now: power level).
And in Destiny 2? Now the power level is fixed at the time of discovery. This applies to both legendary and exotic engrams.
The power level is fixed, so hoarding the engram doesn’t make sense. It’s best to fly to a Cryptarch immediately and decrypt the engrams. The chance is high that you can make use of them.
Radiant Engrams – The Jewels
Radiant engrams can be obtained once a week for various milestones. There really is something for everyone; you can earn these engrams in the Crucible or by completing challenges in your clan.

The special thing about these engrams is that they always contain gear that is above your current power level (up to the maximum). Many Guardians wanted to take advantage of this situation by completing milestones but not claiming the engram yet.
They wanted to wait to redeem the engram until reaching a specific power level at which they rely on these engrams (roughly around 265 – 270). But Bungie has put a stop to that.
Because radiant engrams are automatically decrypted based on the current power level precisely at the weekly reset on Tuesday at 11 AM and added to the inventory.
If you want to “farm” these radiant engrams, you can only do so until shortly before the weekly reset. Hoarding them for weeks won’t work. Many Guardians learned this lesson the hard way during the first reset.
What do you think of Bungie’s engram policy? Let us know in the comments!