If you swallow a pill, the liver “metabolizes” the hormones (example Allopregnanalone is a metabolite of Progesterone). This can be good and bad as your body needs metabolites of your hormones (they get made during a normal reproductive woman’s cycle) but also it’s not the main point of taking the drugs, which is to get the hormones into blood circulation presumably bc they go everywhere in the body including crossing the blood brain barrier and have impt (sadly understudied) helpful impacts on a woman’s brain along with her other organs. You can absorb via skin (patch or vaginal pessary) and get into the blood bypassing the liver. You definitely want to do this with estrogen to avoid risk of blood clots which increases when you swallow estrogen and it goes to the liver. Keep in mind gel pills (Prometrium) can be taken as a pessary (ie put into the vagina rather than swallowed).
When you’re talking about the difference between patches and gels I think you’re talking about what works best for different peoples skin (best for absorption and avoiding skin rash or other bad reaction). Some people respond poorly to progesterone but some only respond poorly to certain ways of getting progesterone and certain doses, so sometime you’re just trying to find the way to get the drug into your system without side effects.
Of course talk to your doctor and ask you doc about these things.