Networks jamming up with spam transactions plus there aren't that many miners mining the new blocks created
No.
Network jamming up with recommended fee paying transactions.
Spam transactions will not affect your transaction. Unless your sending spam, are you?
If you pay recommended fee, you will be prioritised over spam.
The problem we have just seen, (and will continue to see), is because blocks are full of non spam fee paying transactions.
This is Cores fee market in action.
You say "there aren't that many miners mining the new blocks created" - complete BS.
Transaction malleability is not about fees, it is more dangerous and serious: a whole in the cryptography lets the spammer to replicate a transaction with different hash (same data) if one of such useless copies happen to be confirmed prior to the original one it will not be confirmed (the transaction has taken place though , the receiver has received her payment and the payer balance has been justified and miner has got her fee, every thing is ok ) BUT the transaction hash , one which is usually used to check all these, seems to be orphan or even having rejected status! (as double spend).
Idk we are experimenting this or not, but as far as 'transaction malleability' is to be considered, there exists no cost for this attack it has nothing to do with miner fee.