Gold is also money, yet it's inherent high friction in use and lack of granularity means that nobody actually uses it for anything.  It's just stuffed into bank vaults as a "reserve".  The market deemed gold was an invalid form of currency and needed something with less friction and higher granularity so gold IOUs were born, thus leading to fractional reserve.  This puts a glass ceiling on the value of gold no matter who is trying to manipulate it up or down.  Gold creates and spawns layers of trust based systems due to these inherent weakness discussed.  

For Bitcoin to pass whatever glass ceilings it has, it probably needs at least enough TPS to process all of the world's large, high value transactions such as houses, cars, yachts, etc.

At 7 TPS, you can do 604,800 transactions per day (probably closer to 500k in reality but whatever).  

There are 14,000 houses and 43,000 cars sold per day in the US.  1 meg blocks are probably too small, or dangerously close to maxing out if handling all of the world's house and car transactions.  We don't need to scale to gigantic blocks, but something like 8-10 meg blocks is probably what it needs to scale to for being a major player in the world where most things of several thousands of dollars in value are done on-chain.  This is an achievable goal without things like the Lightning network existing.