Chinese native speaker, pretty good at Japanese (passed N1 many years ago). I actually think spoken Mandarin Chinese is a lot easier to learn for most situations except for a complete beginner:

• For a complete beginner, Japanese has one of the (if not the) fewest possible valid pronunciation among all languages. There are literally only ~50 "alphabets" (officially only 48, there are a few weirder non-official ones), all of which are easily pronounceable. Mandarin Chinese also has a pretty restrictive pronunciation set, it's simply that the tones (especially the 3rd) tend to trip ppl up
• Past the complete beginner stage and Japanese becomes noticeably more difficult than Chinese. Japanese grammar is an absolute nightmare, and you do have to know most of the grammar rules; not to mention you can have multiple different ways to pronounce the same word... Whereas Chinese has almost no grammar and overwhelmingly relies on memorizing vocabs, which someone who only wants to speak doesn't even need to worry about how to write them (which is most of what makes it difficult)
• Just to clarify, both Chinese and Japanese are high-context languages (to compensate for way too many words sounding exactly the same), so the fact that a local might not understand you often has less to do with shitty pronunciation, and more to do with that the entire sentence makes no sense. A lot of Chinese ppl understand regional dialects (which are pronounced very differently) just fine

The Chinese dubbed anime thing is for Chinese ppl too. JP has a very robust seiryu (voice actors) industry, and a lot of CN/KR dubs just simply can't catch up with the voice-over quality... A good example, think Genshin Impact: it's a Chinese game but the default VA is JP. I highly doubt this has anything to do with the language themselves. The language themselves... I've heard some ppl say that spoken Chinese sounds "angry", might have something to do with the tones. Not sure about Japanese...