Several things are happening in the market for PPC agencies.
1. Companies are switching from brick & mortar to selling online for delivery or curbside pickup. This will be a good client short term but as things normalize this might be discontinued or greatly reduced.
2. Companies that were previously DIY or working with another agency are looking for a miracle worker to resurrect their business from COVID-19. I would avoid getting involved here as you are being set up to fail.
3. Some businesses are booming and want to build on that success. These should be clients you can hang onto but will be less valuable when the hoarding stops and people get back to work.
Keep in mind that most agencies are still way down in revenue as many clients are unable to provide services or have very little demand for services.