Hi Dustin. I have lived in Chino Hills most of my adult life and have commuted all across the LA area. The answer to your question is: it depends.
The most achievable driving commute from Chino to LA is if your job is anywhere east of Western, like Downtown, Arts District, Pico Union, Westlake, Echo Park, Silver Lake, and, at most, Koreatown, East Hollywood, and Los Feliz, will be about 35-40 miles from Chino. Once you cross that threshold of Western, you're now braving longer mileage and time into the Westside and Beach cities like Santa Monica, Venice, Palms, Culver City, Westwood, Century City, and so forth. Those points are 40-55 miles from Chino. As far as time commuting by car, I've found that an average speed of 25 mph is a handy go-by to estimate peak traffic congestion, and 75 mph for off-peak travel.
So that breaks out to:
East of Western:
35 miles away: Peak, 84 mins, Best, 28 mins
40 miles away: Peak, 96 mins, Best, 32 mins
45 miles away: Peak, 108 mins, Best, 36 mins
50 miles away: Peak, 120 mins, Best, 40 mins
55 miles away: Peak, 132 mins, Best, 44 mins
These numbers reflect what many find true about LA--when freeways are empty, it's a wonderfully accessible place, but in peak traffic, it can be demoralizing.
As you probably know, there aren't a ton of public options around Chino, but there are two good ones if you plan accordingly.
First, there's a Metrolink that runs from the City of Industry station (off 60 and Grand at Golden Springs) to Union Station in Downtown. The trip is a consistent 35-40 minutes and runs about $17 round trip (some employers subsidize this). When I worked in Downtown, I used this option a lot, because I avoided all freeways, had a predictable schedule, and received subsidies from work. You would have to drive from Chino to the station at Industry, which has a large, free park and ride. That drive is about 12 miles (15-20 mins). Again, this works best if your job is Downtown or near it. If you need to get further, you'll have to rely on the Metro lines, which of course adds time. If you wanted to work in Hollywood proper, for example, you could drive 15 mins to Industry station, 35-40 train to Union, and 20 mins on Red line to Hollywood/Western stop (similar to peak driving, but less stressful and intense).
The second option is the Foothill Transit bus line. It leaves daily from the Park and Ride at Chino Ave off the 71, which is like just 5-10 mins from wherever you are. The bus is about an hour straight to Downtown and, like the Metrolink, is generally reliable and convenient, but most ideal for Downtown travelers.
As someone who spent 9 years doing these commutes, my advice is to find jobs generally east of Western, and even then, think twice about it, and try to get your peak commute to never be greater than about 1hr 30 each way, as anything more will wear on you quick. For jobs further out, it's worth saving money and trying to get a cheap apartment closer to work. I intentionally left out commutes to other areas, like Long Beach, Orange County, etc since your Q seemed focused on LA, but those would be similar calculations.
Hope this was helpful!