Bitcoin price continues to increase and that is what matters, the system is stable although not very reliable because one can never know when a transaction will be confirmed, if more transactions are important people can use some other coin like litecoin.
As far as investment goes, bitcoin is perfect as it is...
The security of the blockchain is king, without it the price will go to zero.
Which leads into the hesitation to change things it would seem. Logical but.. I stand by my title.. I offer no great solution just something like a linear increase in size so mores law dominates any linear increase but that isn't much of a suggestion.. All I know is 1MB in 2040 will just be overly silly.