The parts that are easy to get are typically pumps, gaskets, filters, motors, etc. The parts that wear out in the normal use of the machine. Doors, frames, etc. are sometimes not available at all, sometimes available at ridiculous prices, and sometimes (rarely...) available at a reasonable price.
My general feeling on appliance parts is that the replacement price for parts is typically 5x - 10x the cost of the same part when included as part of the appliance. That is, a part that is a $5 part of a $500 appliance when built might sell separately for $25 - $50 as a replacement part. Which means a major part that costs $25 as part of the original appliance might sell for $125 - $250, which is likely better spent towards a new dishwasher.
However, you may have one other option, because the appliance is relatively new. Ordinary warranties cover factory defects and, in some cases, cover wear & tear that is beyond normal expectations (e.g., a motor that isn't defective per se but that wears out in 10 months instead of 10 years; but not a battery because battery life is extremely variable). There is no hiding that this is not normal wear & tear - if you made a regular warranty claim the technician would take one look and walk away. There is a small possibility that if you paid on a credit card that the credit card company provides an extended warranty (typically doubling the length of the original warranty) but that will also usually exclude accidental damage.
But there is one more option. There are "extended warranties" that include accidental damage coverage. Not all extended warranties include this coverage, so you need to read the fine print before you buy one. I am generally not in favor of extended warranties on consumer electronics, with the exception that at times I have recommended them for people sending a kid off to college because one "laptop fell out of backpack and cracked the screen" makes the extended warranty worth it.
On major appliances, this is typically based on purchase price. I bought one with my oven many years ago and it paid for itself when I needed some repairs after the regular warranty. On the other hand, I have seen people way overpay for extended warranties that are actually extremely limited service contracts, so you really need to look at the specifics: up-front cost, likelihood of using the service, cost of typical repairs if you don't have the extended warranty, exclusions, etc.
The other key thing is that some manufacturer extended warranty plans can be purchased after the initial appliance purchase. The timing varies - could be anything from "30 days" to "1 year" to "until original warranty expires + 'n' days" to "whenever". In addition, you need to determine whether pre-existing conditions (damage prior to signing the contract) are covered - sometimes they are, sometimes they are not.
If all those conditions work - still able to get an extended warranty, existing damage covered, accidental damage covered - then Samsung Premium Care is a possibility. It clearly includes accidental damage. I do not know whether you can still get it on your machine (timing from purchase date, etc.) or whether it includes damage that occurred prior to the contract.
Note that I am 100% against manipulating the system. I do not in any way condone ordering a contract, waiting a week and then saying "oops, this just happened the day after I signed up". That is abuse of the system and wrong. But if the contract allows for pre-existing damage then this is a great solution.