Firstly, congrats for taking your car to the track: that is legit
Secondly, when learning to drive on a track many an instructor will advise their student to leave it in a 4th or 3rd gear (circuit dependent) to reduce workload and focus on what is most important when learning the craft: vision, being smooth with controls, following proper line, etc. At first it is an absolute info overload hence eliminating shifting make sense at this stage.
But, when one is beyond the basics and tries to increase pace it is crucial to be in a right gear for each upcoming corner exit.
Simply said, if one is in too tall a gear an exit speed will be compromised - zero question here. Also, such gear needs to be selected prior to turning into a corner. So if you come off a 4th gear straight into a slow hairpin, one would need to downshift to 2nd gear before corner entry. Etc.
The main issue not heel and toeing (or letting rev match do it for ya) is a possibility of locking up rear wheels (in addition to putting undue and sudden strain on a drive line when revs arent matched). When the rears lock up a car can spin instantly, or at best get unsettled. The former can lead to an easy wreck, the latter is highly undesirable as the key is to always keep a car as "flat" and as well balanced on all 4 contact patches (tires) as possible - at all times. Thats why "smooth is fast" (at least to a point and not at all meaning "slow and sleepy" but the idea is to maintain balanced platform as much as possible).
Now, some drivers, even seasoned amateurs, dont heel and toe. Not because this is better, but because they have never learnt how to do it. Some "cheat" by just blipping the throttle AFTER they brake but before they shift, etc. None of it is desirable or recommended over a proper heel and toe technique. None of it will allow the driver to maximize corner entry speed and smoothly transitioning to lower gear(s) necessary for an upcoming corner exit. Of course not all corners require downshifts. Some fast corners may only require a little braking input, or even just a slight lift of a throttle.
Bottom line, i dont understand why anyone would suggest that matching revs before a downshift would be a "crutch". The latter would suggest that some other technique is better, or achieve better results. And that is simply NOT the case. Even automatic dual clutches will blip to match revs. I would say that an automated rev match function is a crutch, as the car performs the heel and toe automatically and flawlessy. But thats a good thing and majority of even seasoned track rats will gladly use it as it reduces their workload. I had to heel and toe in my previous 2 cars. Had modified pedals to make it easier, etc. Was pretty proficient at it, yet
I am happy to use rev match because it reduces my work load and since i am an old dog, the fewer the tricks i need to perform the better
Lastly: anyone suggesting that a heel and toe is not necessary for maximizing pace around the track is not legit and/or not as fast as they could be, or drives an auto of some sort, or a stock car (in which you brake with your left foot and use your right to just blip a throttle when downshifting - no clutch necessary).
NB when one first starts with a track hobby many folks on a paddock will look (and sound) like accomplished pros, but sometimes spew absolute bs. Choose your mentors wisely: learn at driving schools like PCA, or BMW who train their instructors to become accredited and competent coaches. Run away from folks who are not humble and friendly and who talk about themselves and their track/racing "war" stories, more than about you and your learning needs
Cheers!