There are plenty of ways to learn/adapt strategies from those who perhaps have more resources, but definitely a measure of intelligence and are generous enough to share how they reached an achievement.
I wasn’t prepared to use huge resources for this tower run, however I can still learn from someone who did, and definitely see ways I could use whatever resources I am happy to use, more intelligently next run.
It isn’t luck that produces a deep bench, its a great deal of forward planning and time investment (which can be done cheaply over time)
One thing that strikes me about the tower is that a great many S1 heroes have a use there, and are perhaps (taking into account the boosts available as you progress+ the resrictions) more useful than many of the fancier, harder to get heroes. Quintus and Thorne for example. I have levelled dupes of many S1 4* especially healers, and could not have completed the tower without them.