Is there any need for new file systems or GTFO we are full?

Specialist file systems will keep emerging for various reasons such as accommodating new hardware better or for secretive purposes. No doubt continued efforts are simply to make a better mouse trap, like addressing shortcomings eg speed or less load on a drive or making recovery of data when things inevitably go pear shaped ... more optimistic, either by ensuring it doesn't get borked in the first place or actually providing something a tool can work with.

One feature I wish filesystems had is transaction support, ie:

  begin transaction
    create file X if it doesn't exist, otherwise abort transaction
    write some stuff to file X
    open file Y
    overwrite some data in file Y
    if  commit transaction
  end transaction

Nested transactions would be required as you'd have no idea whether you're already in a transaction.

Something like this can be coded (painfully) with renames, but it's unreliable, hard to test, and hard/impossible to coordinate with higher-level modules.

Wonder if LTFS satisfies all needs for LTO tapes. It seems to be the only FS that storage medium currently has.

There's also all sorts of FSes that aren't based on hardware, like eCryptFS/EncFS for encrypted directories, s3fs for using AWS S3 as an FS, sshfs for remotely mounting a directory from another machine, btfs for mounting a bittorrent as an FS. The number of things that can be done as an FS seems almost boundless.

There is always room for new ideas in filesystems. The question is are those new ideas good enough to pull eyeballs and bits? Even if the ideas are great, between the complexity of filesystems, risk associated with them and deployment of them -- the most likely "successful" new filesystems would be backed by a large player in the OS space.

revision control systems are littered with filesystem projects that have died on the tree.

As an individual or professional I am not excited by new filesystems if there is any risk of data loss at all.