I am a molecular biologist (but I am not your molecular biologist, or however these disclaimers go.) My lab has done a few gene editing projects using CRISPR, and I have plans to do some projects myself. It really is a huge advance in the state of the art.
It’s a lot easier, cheaper, more efficient, and more reliable than any previous technique. If you want to genetically modify a fruit fly, you just need to spend a few weeks making the CRISPR DNA editing constructs, inject a few embryos, and screen through the second generation flies to find successfully modified flies. Total efficiency is on the order of 10%-50%.
In comparison, previous techniques like P-element insertion are less efficient (~1%) and insert genetic constructs in random locations in the genome. Editing specific locations using homologous recombination is a lot more labor intensive and less efficient, IIRC requiring 3-4 generations with efficiency on the order of 1 in 10,000. There have been many enhancements of these techniques, enough to write a small textbook on the topic, but even the best techniques aren’t anywhere near as good as CRISPR.
(FWIW ThermoFisher probably won’t sell to any schlub on the internet, their website is intended for customers in academic and private labs. But you don’t really need a kit…)