TL;DR - Strip away all the extra stuff that’s been added to the game and get back to the core elements. Significantly nerf payouts to encourage trade, piracy, smuggling, mining and salvaging.
actually, i've played in a very similar fashion from day 1. i.e., never did trade exploits, 0 passenger missions total, made 85% of my cash in small ships, rest in mediums. only ever used the conda for a bit of mining because that's what that barge seems made for, and couldn't care less about faction ranks and the other two flying bathtubs. in short, always played my way. even the little engineering or credit earning i've made i did enjoying the process and with complete disregard for 'efficiency'.
that way you can enjoy elite quite a long time. it depends on your playing time, though, everything gets old, specially if you play solo, and with the years and the updates i've been playing less and less (but still am).
at some point i considered giving away my small fortune and clearing save. i decided not to, here is why:
i think the game design is too dependent on the really lame and ubiquitous mechanism of gating content: credits, engineers, guardians, permits ... you name it. while some mechanics are cool they are all subordinated to the grind. while this is not at all uncommon in nowadays games, it comes across as a really moronic mentality and elite really pushes it to its limits. the thing is, thanks to years of casual gameplay i have now all that unlocked, which means most of the content and options are available to me: permits, ships, upgrades. which means i'm in position to do anything i want, and if frontier tomorrow releases some new feature i find interesting i can swiftly check it out. since i am perfectly able to play without falling for frontier's stupid skinner boxes there is no need nor advantage in handicapping myself. i already do that in my regular gamestyle just by ignoring the carrots hanging from the sticks, but i want to maintain the flexibility of making exceptions when i consider them appropriate, not frontier's design team (which, honestly, should have stuck with theme parks, no hard feelings).