Assuming this post is ernest, it's pretty simple. Companies defer profit now because they see growth opportunity ahead. They are betting that if they lose $1B this year, over the next 20 years they'll make up this years loss and more. So Lyft thinks that by losing $1B this year, they can make, say, an extra $1.5B over the next 20 years.

It's possible they are wrong, in which case investors will lose money. However, if they are correct, the investors will get good ROI. Depending on the investor's risk profile, this may/may not be an appealing proposition.