My TL;DR takeaway from Alden's post is this: the security of the Bitcoin network once it transitions from mining based rewards to fee based rewards is entirely dependent on adoption. If there is adoption, tx fees will be sufficiently high thereby securing the network.

Therefore: if you want to secure your future corn, focus on increasing adoption today. Such as smashing lightning on this post, or writing your own post, or supporting strike, or donating via BTC, or or or