Bungie is sending the extraction shooter "Marathon" into its next testing phase, delivering a purely PvE playground for the first time. Whether it can save the player numbers is uncertain.
The mid-season update for the current alpha/beta phase launches on July 21st. The focus is on the limited-time "Vault Breaker" mode, which is intended to bridge the gap to a permanent PvE component in Season 3. The studio is thus directly addressing the ongoing criticism of the game's pure PvP focus and the declining player numbers in the genre.
Roguelite structure against the UESC faction
The new mode abandons the classic PvPvE concept of the standard maps. Until August 4th, solo players, duos, or trios will fight exclusively against AI opponents in the Cryo Archive. Bungie is using a roguelite structure for this. Players start with a weak, free "Sponsored Kit," which is gradually upgraded for the current run using the event currency "Vault Data."
The catch remains the loot system. Equipment and weapons found in the archive during the run cannot be permanently extracted. The only exceptions are event currencies and cosmetic rewards. Those who want to unlock permanent equipment for the regular game must exchange the event currency in the special event shop.
Strict limits on grenade spam
The sandbox changes drastically alter the meta of the standard modes. Bungie is drastically limiting the number of grenades and shields players can carry. Before a match, a maximum of two defensive or offensive throwable items are allowed. Players who want more during the match must find them on the map. The system effectively prevents the uncontrolled use of bubble shields in the endgame.
The weapons receive the usual damage adjustments. The WSTR shotgun receives increased base damage but loses all precision multipliers and its range is reduced. The dominant D54 combat pistol also loses multiplier strength and range. It now requires three precise bursts instead of two to kill standard shields.
Bungie is using players as guinea pigs for the upcoming PvE mode. This is legitimate, but it doesn't alleviate the general skepticism surrounding the pure extraction concept. Those who already play "Marathon" will take advantage of the balance changes and cosmetic additions. For skeptics, the two-week PvE excursion offers a nice opportunity to test the shooting mechanics without the constant pressure from enemy trios. However, this temporary test phase is far from being a real reason to buy the final version.
Bungie has released a full preview of the mid-season update. with this link published.

It won't save the game either. Bungie's community wants Destiny 3 or continued support for Destiny 2.
I'll give it a try; the PVP mode wasn't for me in the long run.