Janaque  The specs that matter are a good graphics card, but only up to the level of a desktop 3060 or so, even at a high resolution; and the speed of the processor running single-core or lighter multi-core loads.  Sims 4 can only use four cores, so it doesn't benefit from a CPU with more than 6 (two for Windows and light background tasks); the speed of the cores matters more.
What can also help is changing some values in the GraphicsRules file.  Especially on higher-end machines, you can tell the game to render sims and objects at the highest quality at greater distances to avoid the performance penalty from switching between LODs.  The problems that arise from not doing so affect even the highest-end PCs, so it's not a question of upgrading the hardware to avoid it.
If you'd like help picking out a specific computer, please list your budget and country, as well as any other details that matter to you, and whether you want a laptop or a desktop.  If you'd like a second opinion on something you pick out yourself, feel free to link it.