We live in a system with groups jockeying for political power. The groups continue to maintain power as long as they continue to convince enough of the populace to vote for them. They do this in various ways. One way is to form a coalition of subgroups and promising such subgroups favors. Another way is to convince the populace that they are all in it together. One favorite technique is to raise the spectre of an external enemy.

Some current enemies: China, global warming, coronavirus, immigrants, racism.

The longer you live, the more you see these techniques repeated over and over. The situations are rarely as the political parties make them out to be. The political parties mostly lie since entities that don't are disadvantaged at obtaining political power. People as a whole are too easy to manipulate so it is to your advantage to lie.