This is not them flaking on you for the date. this is you failing to set up the date in the first place. In my experience, yes women are flakey...but i haven't had much trouble setting up dates via tinder. Flaking once the time comes for the date....yes. If they have high interest and you don't muck it up...a lot of times you're good to go as long as you push for the meetup, and if you dont make any big mistakes or be real awkward....especially if you're physically attractive.
First off, work on your text/online game. Online dating game is extremely similar to texting game. In fact, most of it should take place via text because you NEED to transition to texting VERY quickly after opening them. I would say an average of like 10 messages back and forth, if not less, before you bounce to text. Once you bounce to text, you cannot pu$$yfoot around setting up the meetup. You have to assume that many of the girls arent going to go for it, so it's a complete waste of time sending dozens and dozens of messages to each girl. At that rate, you are never going to meet up. Establish JUST enough comfort via texting so that she knows you're not a creeper and feels relatively comfortable. If she's not feeling it, move on.
HOW YOU ASK them is important. As well as WHERE you are meeting them. I've found that, overwhelmingly, coffee dates are the absolute best. It's a low-pressure, public place. It's cheap so it doesnt look like you're trying to buy her way into her pants, unlike an expensive dinner or something. Meeting up for a drink is also an alternative.
When you ask them, it's normally not a good idea to BAM just come out with it. It's nearly always a good idea to both seed the idea early in the conversation as well as slip it in casually when you do ask her. Much like a kiss close, It should not seem like a sudden, big deal. It should merely be a natural progression in your getting to know her, with you as the confident man who has no trouble leading the interaction.
And if they're giving you their number and asking to meet up....be skeptical. First off, just like my dear mother said years ago, "if something is too good to be true, it normally is." They're often low quality and/or much less attractive in person. You should expect at least a little token resistance, unless you're looking for the bottom of the barrel. If they straight up ask you.... dont be so easy. Flip the script and joke around and act like you are the skeptical girl who's afraid of meeting up with a "rando" or a "catfish" because they might be a psychopath or a stalker or something.
Braddock's guide to phone and text game was a vital resource for me. highly recommended.
