So, it’s clear more people get funding than tenure. However, difficultly really is a function of the success rate of each track and the amount of investment they make in it. Still, for the average collage freshman tenure is likely much harder.
The average college freshman is not trying to get a phd. Picking a low starting point like that is just a way of making it appear more difficult than it is. The more appropriate number is the number of phd's attempted.
I didn't respond to your comment because the right denominator is going to depend on who is reading this thread. A Stanford CS major with a 2400 SAT whose parents successfully founded a tech startup is coming from a dramatically different pool than a data-entry drone with no college degree and no technical skills who figures that a weekend startup is his ticket to riches. The former's chances at both getting a funded startup and a tenure-track position are pretty good. The latter's chances are effectively zero. The latter falls into the pool of people who could conceivably "start" startups, but doesn't fall into the pool of people who attempt Ph.D programs.
You are not a lottery ticket.
Realistically, I think that tenured professorships and funded startups largely draw from the same pool of people and hence have the same denominators. That's why I focused more on the numerator. If you have the skills, dedication, and knowledge needed to become a tenured professor you usually (not always) have the skills, dedication, and knowledge needed to found a high-growth company, but there are more opportunities for the latter around, as well as fewer gatekeepers that can exclude you for arbitrary reasons.
As of 2016, academic institutions hired 21,511 full-time, tenure-track professors [1]. Your odds of getting tenure given that you're in a tenure-track position vary by institution, but seem to range from about 75% at elite private institutions to 90% at state schools [2]. Figure about 18,000 professors were hired into positions that will eventually grant them tenure.
AngelList lists about 30,827 companies at the Seed or Series A/B/C stage [3]. Crunchbase has 33,577 funding rounds that occurred within 2016 [4]. The former stat has issues in that it includes funding rounds over a broad time period, and the latter potentially has issues with multiple funding rounds for the same company happening; however, given their general consistency and the existence of funded companies that do not appear in AngelList nor Crunchbase, 30,000 companies funded per year seems about right.
The average tenured professor salary varies heavily by field, but the Chronicle of Higher Ed reports it at $104820 [5], Glassdoor at $70385 [6], PayScale at $71993 [7], Indeed at $66921 [8]. There were 12,688 mergers & acquisitions in 2018 [9], the vast majority of which were for undisclosed amounts (companies do not have to disclose the transaction if it's for < $75M). Given the distribution of the ones that are disclosed, it's a good bet that most of those are for between $1M-20M (I've heard $1M/engineer as the going rate for aquihires, where the team succeeds in delivering a product but the product fails in the marketplace). This is still roughly 100x what the tenured professor makes though.
[1] https://www.aaup.org/sites/default/files/10112018%20Data%20S...
[2] https://dynamicecology.wordpress.com/2014/07/21/dont-worry-t...
[3] https://angel.co/companies?stage[]=Series+A&stage[]=Seed&sta...
[4] https://www.crunchbase.com/search/funding_rounds/a416e3bdb17...
[5] https://www.chronicle.com/article/How-Much-Did-Professors-Ea...
[6] https://www.glassdoor.com/Salaries/tenured-professor-salary-...
[7] https://www.payscale.com/research/US/Job=Tenure_Professor/Sa...
[8] https://www.indeed.com/salaries/Professor-Salaries
[9] https://www.statista.com/statistics/245977/number-of-munda-d...