A bit simplistic. Both ideologies have many variations in how they manifest themselves and can be modified by time, place and culture. A Fascist nation in Asia would have some differences to one in South America. Same with manifestations of Communism.

Both have positive aspects when taken alone and isolated from the corrupting influence of humanity. The premise of communism, on its surface, seems quite utopian and nice. Everyone wants to feel equal. If you think deeply on it, people really don't want to feel equal to everyone else... they want to feel better than someone they see as not as skilled, talented or smart as they are and they want to be compensated for that.

Fascism can feel very organized, managed and secure. If you put in effort it will be rewarded. If you toe the line, you will thrive. Stick to the rules and you can have a rewarding life based on your own merits. The dark aspects are mostly obvious.

Similar thinking happens in religion. You want to support all the dogma that aligns with what you want and believe and push aside all the stuff that doesn't.
Communists advocate for a classless society where all property and resources are owned and controlled by the state for the people, with the aim of achieving economic equality and social justice applied with the same brush for all. Communists also believe that the state should ultimately control all aspects of society: economy, culture, and education. They also prioritize the collective good over individual rights and freedoms believing that true freedom can only be achieved through the elimination of social and economic differentiation across all members of society. They reject racial and ethnic divisions, including cultural ones, and advocate for a world without borders, nations or any ethic or cultural divisions.

Fascists support private property ownership, but favor strong state control of the economy and strict regulation of businesses. They believe in a strong state, but one that is focused on promoting the interests of the nation and often the ruling party or it's leaders, with a strong militarism and expansion of national interests beyond their borders which can include land annexation but also political control. The nation has priority over individuals, but individual loyalty and sacrifice to the nation is high priority. They favor traditional expressions of national and cultural identity, often promoting a supremacist view of their own culture.

Ideologies of all sorts are subject to the corrupting influence of mankind regardless of race, gender, sexual identity or spiritual inclination. Humanity is most often noble and real in the intimate moments between individuals and small groups rather than on institutional levels.

It seems cynical to position myself with a view that we are all deeply flawed and want something to rise up and sweep us off our feet and save us from ourselves. I feel those sorts of things tend to work out in the short run but quickly corrode by the poisons we excrete ourselves.