I myself was using several mod managers over the years since 2006, although for a long time I sticked to manual install.
OBMM was the first I think. People kept asking, I provided OMOD-ready versions of my mods and had to give it a try myself for programming their install scripts.
I'm still using it nowadays, but not as my manager anymore. Its "Utilities" menu still comes in very handy in regards to Archive Invalidation, Steam BSA timestamp fixing (not a Steam user myself though), BSA archive browsing and extracting whenever I need a Vanilla resource for modding it, and OMOD-to-ZIP conversion for those few mods only available as an actual OMOD still.
NMM was the second, or third, mainly due to me wanting to know it so I can explain it to those who ask (a part of the job kinda deal).
Didn't yet switch to Vortex (my current mod installation is way too complex for a successful transfer) and never got Mod Organizer MO/MO2 running in my Virtual Machine (probably a problem with creating virtual file systems inside a virtual file system or similar). So I can't vouch for those.
Nowadays I'm back at Wrye Bash's BAIN, as it's the most straight forward and uncomplicated of the bunch (kinda keep telling it "automated -manual- installs", as every option inside a BAIN archive is in fact a manually installable mod).
Other than f.e. OBMM BAIN also reinstalls files from previous installed but overwritten mods, when a newer installed mod was uninstalled and took all files it overwrote with it. OBMM would have left a hole of missing files.
But all in all Oblivion is a very old game and the majority of its mods are almost antique, from a time where there was neither managed installs nor standardized folder structures in mods releases. Not every manager understands every other manager's mods. OMODs can only be installed by OBMM (afaik), BAINs can't be installed by either OBMM or NMM/Vortex(?), and certain manual install packages (requiring you to "rename" optional/alternative files) cannot be installed by any (straight away).
So every manager in existence will have problems even "understanding" a lot of (older) mods, and they will need to be re-structured first before they can be installed. But then "every" mod manager can install every mod, or at least I can make them so they can be installed in every manager I choose.
It's really only a matter of personal preference at this point. Just stick to the manager you know best and fix those mods it can't understand.
Though Wrye Bash I was already using long before OBMM, just not for its BAIN (don't think it was even a thing right at start). Its Bashed Patch is invaluable nowadays where everybody wants to have at least 50+ mods. Load order is important, yes, but in this old game load order alone can't fix everything.
Did you know, for example, that the game's own plugin merging on load does not even distinguish between male and female parts of race records at all? The race record loaded last will be taken into account 100%, male and female parts at the same time. This is already a known issue when using a male and a female body mod. Their plugins won't mix without undoing each other's changes. Add other cosmetic mods or even character overhauls into the mix and you will loose a whole bunch of vital features.
Now, yes, there's always been manually-made compatibility patches, for use of one body mod together with another or together with a certain cosmetic mod or character overhaul even. But how many patches from 3rd party authors are you going to look up, search and install, until even the patches start undoing each other's changes? Make your own patch merging "all" race-affecting mods you got? Damn well "I" can do that, no problem. But is it just as simple for everybody else?
With the Bashed Patch and the community-and author-collected and -sanctioned over the years Bash Tags (tiny snippets at the end of plugins' descriptions telling Wrye Bash which parts of the plugin are the important ones and need preserving, for example only the male parts of a male body mod and only the female parts of a female body mod, or only the hairs/eyes added to X races of a hair/eye mod) the tool will create a patch for you which will have merged all potentially endangered critical changes, and only those, from all conflicting plugins in your load order. And it even overcomes the Rule Of One and the non-splitting of record parts the game's own plugin merging so fails in doing.
Just get your load order correct, click a few checkmarks and let the tool build the patch at the click of a button. With this ever-growing lack of free time for modding I started encountering a decade ago, at one point even I wasn't up for making all my patches manually myself anymore. The single click of the button was soon the preferred choice even for me.