How To "Power-Game" as a F2P in SWGOH
1. Throw away your first account after playing 2-4 weeks and learning the game mechanics.
2. Start fresh, ideally after having restarted a few times to get an optimal first free chromium toon and after having hoarded some energy & challenge reward items.
3. Through careful choice of toons farmed, be capable of taking top 50 squad arena payout daily. By mid/late game, this should improve to taking top 20 squad arena payout daily. By endgame, this improves to being able to take top 1-2 payout daily. Ditto for fleet.
4. With a daily gem income of 800+, consolidate the power of your squad and fleet arena toons; then expand to gear up Rancor and hAAT squads (to take top guild payouts in those events).
5. Rapidly power up other toons on demand, and enjoy the rest of the game.
I did a half-assed job at all of the above, but eventually got to top payouts after 10 months of play. (After which, I could buy a full stun gun every 2 days.) Friends and guildmates that optimized their start, were already getting top payouts at the 6 month mark; they're now well over 2M GP.
That's how it can be done.