+1 with Kadachiman.
In GW3, I'm running a medium-sized planes comany in Glasgow. I've been attacked there 7 times. The only survivor is the one that went here with smaller planes. He "bullied" me by reducing my income on many lines. Yet. It's part of the game. I've done it on countless lines(most of the times against a company based à the other side of the road), and that's the way the game is meant to play.
There is place for many companies in this game. Just, make sure you go where there is some place. Especially when learning. That was my first real game, this GW3. I went to Glasgow because it was empty at first, and fleed to smaller empty bases as soon as I was attacked there. No regrets. Where noone is, there is place to grow.
Had I gone first to Heathrow, I would have been exterminated by the local behemoths. I know I'm not as good as them. I had to find a good balance between potential & lack of opposition. There are still a few good starting points in GW3(as Tahiti), with lack of opposition & juicy potential routes. Not as good as Glasgow in 1995, but hey, game is running for a long time.
Unlike Kadachiman, I did never settle to a base with already someone installed. Matter of strategy. It pushed me to smaller airports, with less potential, where I was quiet to learn the game. And I did learn a lot
_Learn that a Short range route is likely to be attacked by smaller planes, and don't put a 737 for a 100pax potential route with 200NM of distance. You'll be destroyed. I've lost a lot of money like that, before learning
_Learn to stay focused on specific markets, and have at first a maximum of 2 kind of routes(for me, it was 737 & CRJs(replaced later by A148s)). I've lost a lot by temporary using old IL62s for raising up RI while waiting for 737NGs(Communality costs plus one extra plane category, XL, the costliest).
_Learn to maximize plane use(with red eyes flights & 7-days schedules), so that the burden of leasing(or purchasing) planes is spread amongst more lines.(flying Glasgow-Cairo by day while keeping the plane idle at night was plain costly stupidity).
_Learn to avoid technical stops, at least in the modern world. I did a try in 2020 between Nantes & Le Lamentin, with a tech stop in Horta. My A148 was 20% full. When replaced with a 737MAX7, LF went up immediatly to 90%, despite the capacity being nearly doubled.
_Learn to manage your prices carefully. Each line is different, and deserves some pricing baby-sitting.
And learn many other things I don't know yet.
One of the leaders of my alliance has been attacked in 5 of his 6 bases by the same company. He's struggling, but he's still in the green. That what Kadachiman means when he says that good players cannot go BK. Such skilled players will always survive, find a way out the pressure. For example, he replaced all his 120-seaters by 90-seaters, while moving the 120 seaters to his lone safe base, reducing the costs while not changing the income.
That's strategy. That's fun.