Can I avoid being bought by or having to buy out my competitors?

In general, Sid Meier's Railroads is relatively simple. What makes it more difficult, are the KI competitors. The trouble I always have is: after a pretty short period of time, I either have to buy their company or they buy mine.

Say the scenario runs for 80 years. After 20 years I'm either bought or out of competition. Without competition it is boring. So I never have any challenge in late game and I'd love to play a full scenario "under pressure".

Do you know of any way to extend that phase where there is competition? Can I somehow prevent that I can be bought? If not, any hints how to come to late game without the game becoming too simple even on highest difficulty level?
If this is not possible generally, is there maybe a map which might provide this?

You do the equivalent of 'social engineering' in that game.

1) Build tracks that wrap around the competitor's tracks, early on. That causes the competitors to build lengthly railway tracks to avoid your tracks.

2) Build signals or a cross-road at the competitors tracks. Put a 1 train that goes around in circles that may cause a collision, against the competitors.

3) Build tracks nearby your competitors. That will cause them to lose business.

4) Bid for exclusive contracts. That will cause your competitor's revenue to drop to zero.