I think the biggest hurdle to just starting with all grain is recipe formulation/knowing all the different grains and understanding what they contribute.
To me, there is the grain side of things and the hop side of things. And there are many beer yeasts. If you’ve never brewed before you don’t know munich malt from vienna malt from biscuit malt, etc. Or Cascade from Amarillo from Fuggles, etc. Or what yeast is for what. So how are you supposed to put a recipe together and understand it?
This is a big part of where extract recipes can be of value. Extract kits or recipes take most of the grain side recipe stuff out of it and you can concentrate on techniques and getting your equipment to do what you want and also makes the hop part of it more up front. It’s part of a learning curve.
Either way you’ll be following other people’s recipes to start. How do you pick decent recipes that are supposed to make a good beer if you don’t understand ingredients? If you start with a bad recipe you won’t get good results even if you do everything right.
All true and I am in the same camp, promoting an extract kit for first batch. Now it doesn't take much of a recipe to make a drinkable beer, as long as the steps are performed correctly. Two 5 lb bags of generic two-row mashed BIAB and hopped an ounce or two in a 60 minute boil with cascade or other popular hop, pitched with an envelope of US-05 will make a trouble free beer with very few tricks up its sleeve. There is no need to overthink it for the first batch's ingredients, and trying to make the exact clone of Leffe Blond first time at bat is probably not going to end well and will cost twice what a first batch should cost. A lot of even very popular recipes are to my taste and in my view unnecessarily complex. I think a first timer would be overwhelmed, and that is not a desirable entry into this thing of ours. A simple single malt recipe is a not too terribly complicated way to get started.
Still, even a very straightforward recipe isn't as simple as a good kit of ingredients featuring extract, with a bag of blended steeping grains. Everything is picked out and packaged already. No need to ask on a forum "Which yeast is the best yeast?" or "What is the most popular hop?" type questions. You just read through the instructions a couple of times, ask about anything you don't understand, and proceed simple step by simple step. And a very good beer will be the result if all instructions were followed exactly. It's how I started and I was extremely pleased with batch 0001, an extract kit from Northern Brewer called Block Party Amber Ale. I made two more batches using the same kit, and a batch doubling up two kits of ingredients but still for 5 gallons that I called "Doppel Block". And I did I think 4 or 5 LME only batches, no particular recipe, that were also pretty good though TBH while they had more ABV, the BPAA had a nicer flavor, body, aroma and appearance. I moved to BIAB mostly just to save a few bucks per batch. Is the beer "better"? Yeah. I would certainly put my batches up head to head against the BPAA kit, but success, REAL success, with grain, has depended on knowing a lot of TECHNIQUE, at least as much as knowing my ingredients and having a good recipe. The finer points of brewing technique can be a handful to learn and follow on the first time at bat. A good extract kit does away with half of it or more. Clean and sanitize. Steep grains then discard. Add hops and boil. Chill to pitch temp, transfer to fermenter. Pitch yeast. Wait two weeks, keep some water or everclear in the air lock. Bottle it, or keg it.
And a couple of years in, I am STILL ironing out my technique. But those NB kits were dead easy to get spot on. I didn't have to learn to brew, to make them work. And when there is no trial and error, there is a lot fewer errors.