Revenue isn't paying for Capex, operating cashflow does. Intel had around 20 billion operating cashflow in the past 5 years, basically stagnating. Capex was lower last year, that is true, but I would call that an exception. If you want Intel to stay at the top of process tech (which I guess you want), those costs had and will have the tendency to increase. With Samsung spending something in the 15 billion range for its fabs. TSMC on the other hand had about 16 billion operating cashflow last year, clearly growing strongly over the past 5 years. Capex was around 8 billion USD, still lower than Intel's, but approaching.
I can't see a tendency that Intel will need lower investments to finance its future process shrinks (kind of obvious, I know). While TSMC's cashflow is increasing and Samsung has no cashflow issues whatsoever, Intel is the one with stagnant cashflow - simply to its stagnating core business which needs extension (aka volume). It is not an imminent threat but it may be 5-10 years from now.
Samsung's semiconductor business was around 40 billion USD for the past half year. So, for one year, that would be around 80 billion. A lot higher than Intel's, but that includes memory. There are synergies in equipment, fabs, process development etc. from memory to logic, though. Samsung's LSI unit definitely brings lower revenue than Intel's total revenue, but it is growing much faster than Intel's and they are aggressively going into the foundry business, which adds volume. Intel should have done the same by now, but they failed - again.
So, basically you could say that, while TSMC and Samsung are growing their fab volume, Intel is stagnating. This may be ok for the next few years but It will be an issue going further.