BTC proponents will commonly point to low hash rate or "insufficient fees" to dismiss BCH as an "insecure" or "failing" coin. While there is some valid discussion to be had on this topic, the nuances & detail of this point are often ignorantly or deliberately omitted. This simple dismissal is effective because explaining all the related factors usually takes more time than debate participants (or observers) have available to address the finer points. Of course, BTC proponents have to constantly degrade BCH supporters in debates over the real Bitcoin because BCH is a credible, perpetual threat & could "flip" BTC at any time.
In theory, BTC does have better security due to higher hashrate (but not transaction reliability, which is slightly different). In practice, BCH security is fine. Furthermore, BTC & BCH are both racing against time to generate sustainable revenues and in many ways it can be argued that BTC is further from a permanent solution than BCH despite currently producing higher fee revenues (the same way a runner currently closer to the marathon finish line may still be "losing" a race to a racecar being assembled on the starting line behind them).
Today & in theory, yes (but it's not the only or even main factor creating that difference). Today, in practice, not really. In future, in theory or in practice, no.
The interplay of Bitcoin mining ~~.
People commonly believe that more hashrate = more security. While more hashrate is better, it is not the only factor determining the security of a transaction.
The security budget of most cryptocurrencies is composed of two elements: inflation & transaction fees. Revenue from both components is received by the miners when they mine a new block (on average, once per 10 minutes for BCH/BTC).
Other cryptocurrencies may have differing security budget components or considerations, especially if they do not use Proof Of Work mining. The nuances of this are outside the scope of this article, which addresses only Proof of Work mining & Satoshi's 21-million coin inflation schedule shared by BCH & BTC to make a direct comparison.
Expressed as a mathematical formula, the budget looks like this:
Inflation revenue = New coins per block x coin price
Transaction fee revenue = average fee per transaction x average number of transactions per block
Security budget = Inflation revenue + transaction fee revenue
Inflation (new issuance)
(New coins per block x coin price)
First, keep in mind that no-one knows what is the minimum required (floor) security budget. At some point, a blockchain is critically weak enough that miners ~~.