The problem faced by any long-running franchise is how to avoid the law of diminishing returns, with consistency always being the key to keep audiences coming back for more.
These days, it isn't enough to simply rehash everything that worked before but place it in a different context this time around, and one of the main reasons why so many brands keep getting rebooted is that the studios are hoping a fresh coat of paint will cover up a glaring lack of new ideas.
Very few franchises are fortunate enough to have a 100% track record of success, especially once they reach four or more installments, and with the vast majority of Hollywood's box office dollars hailing from their established properties a misstep or two has almost become inevitable at this point.
John Wick, the rebooted Planet of the Apes series and The Lord of the Rings trilogy are some of the very few managed to deliver consistently great follow-ups, but even the most popular and acclaimed franchises in history aren't immune to that one bad movie that undoes a lot of the hard work that went into making them such a success in the first place.
I don't do social media, so like or follow me in person but please maintain a safe distance or the authorities will be notified. Don't snap me though, I'll probably break. I was once labelled a misogynist on this very site in a twenty paragraph-long rant for daring to speak ill of the Twilight franchise. I stand by what I said, it's crap.