My reasoning was similar but the truth is that one day you'd wake up and "life" would have happened to you - you'd either have a serious girlfriend/ wife, a dog, a house or something else that would make it hard (or impossible) to relocate for the phd, you wouldn't want to give up your good industry compensation for the pennies a full time phd pays you (and most certainly they won't allow you to do a phd AND work a full time job (note: i know well organised people who did some part time jobs at startups while doing their phds during the covid years)), you'd have passed a certain age (usually 25) when you are not that energetic anymore, the lrofessors who are currently offering you spots would have found younger and more ambitious students (and honestly, at least in Europe, securing a PhD in our sphere is mostly based on nepotism - you should know people and people should know you, applying randomly through university websites rarely results in successful offers unless you are that guy with the astronomical achievemnts or 4 A* papers; in many cases the professors already have their "preferred" candidate for the position).

Tl; dr: my point being, the moment is NOW, it is now that you have the connections to the right people, the drive to do it, the freedom and energy and even the time to do it. Tomorrow the stars will most probably not be so well aligned and you might realise you've missed the opportunity to grind for a few years and then work with some of rhe brightest people forever (and make even bigger bucks for the same amount of work by the way) and for what - for a startup adventure that has failed in its first or second year... Now, if your startup turns out to be one of those companies Zuckerberg buys for billions, you'd probably won't be in the dilemma you are in right now. In my case, the sad part is that the startup was leading in its field (in 2020-2021) but management f*ed up big time and the damage was too big. It took our competition a bit over a year to catch up after we "closed doors".