Creating cryptographic algorithms at runtime
This doesn't add new security as much as it just shifts it.

Encryption algorithms are carefully studied.  Hmm... I didn't make that emphatic enough.  Encryption algorithms are C A R E F U L L Y studied.   There. That's better.

There are all sorts of tiny nuances to be had when designing an algorithm.  A famous example were some of the  S-Boxes in DES which were developed in a classified environment.  Many thought they were a NSA backdoor.  Several years later, differential cryptoanalysis was "discovered," and suddenly we found that these S-Boxes were the thing that prevented such an attack (thus the NSA had clearly known about these attacks for some while).  This was not a "just got lucky by combining the right bits" thing.  It was carefully thought out.

So the likelihood that your mix-and-match algorithm is breakable is far greater than any of the carefully studied algorithms.  Far greater.  Its basically guaranteed that a dedicated attacker will break your algorithm.  The thing you have bought is anonymity.  By using a publicly accepted algorithm, you are using an algorithm that provides great value to attackers to break.  If they get access to your little secrets, they also get access to things like bank mainframes.

So you make yourself weaker against a reasonably determined attacker while making yourself a bit stronger against a very strong attacker like a state.  Or do you?

A final issue to deal with is that you're mixing and matching known algorithmic pieces, and from your comments the pieces you choose are know in public.  These algorithms were carefully studied, as I said before.  This also means the attacks that these algorithms had to be tuned against are also well known.  So all one needs to do is identify which basic pattern you are using, pull up a list of known attacks against it, and find out what attacks work.  Which puts you in a strange corner where an AI might actually have enough data available to it in a convenient enough form to take your encryption on.

And that would be something a highly skilled attacker would be able to do, so you didn't really solve anything.