Learn Spanish (Latin America): Los obstáculos sucesivos habrían colapsado lejitos. - The successive obstacles would have collapsed very far away.

In Latin American Spanish, adding diminutive endings like -ito to adverbs doesn't literally mean "smaller." Instead, it adds precision, intensifies the meaning, or creates a friendlier, more colloquial tone. Here, lejitos emphasizes that the distance is "very far away" or "quite a ways off," painting a more vivid picture than a simple lejos would.

Since lejitos ends in -s, does it need to match los obstáculos sucesivos in plurality?

No. Even though lejitos ends in an -s, it is an adverb, which means it is invariable—it never changes for gender or number. The -s is simply retained from the original base word, lejos. It would still be lejitos even if the sentence were about a single obstacle.

Why is habrían colapsado used here instead of habían colapsado?

Habrían colapsado is the conditional perfect (meaning "would have collapsed"). You use this tense to talk about a hypothetical past situation—an event that might have happened under certain conditions, but didn't actually occur. If you used the past perfect, habían colapsado ("had collapsed"), it would mean the obstacles actually did fall down.

Can colapsar be used for physical objects falling down, like these obstacles?

Yes, colapsar works just like "collapse" in English. It is commonly used for physical structures literally falling down, caving in, or failing (like buildings, bridges, or obstacles), as well as figuratively for systems, traffic, or even people experiencing sudden exhaustion.