It's grave worship and if you disagree you are wrong
"I asked "The Saudi Ulama say that touching the graves and calling the saints for their blessings is polytheism, so what is your opinion?"
Al-Sayyid al-Sadr replied:
If touching the graves and calling the dead is with the understanding that they could cause harm or render a benefit, then that is polytheism, no doubt about it, the Muslims are monotheists and they know that Allah alone could cause harm or render a benefit, but calling the saints and Imams (may Allah bless them all) with the understanding that they could be an intermediary to Allah, that is not polytheism."
https://www.al-islam.org/sw/node/12750
Yes it is polytheism and this is IJMA as narrated by ibn Hajar that whoever takes an intermediary to Allah is an apostate.
Also I would like to point out the first part of his answer 'it's not polytheism as long as you believe allah is the one behind it', this is always the excuse for every saint worshipping religion. Mary's not all hearing, God just allows her to hear you. However many Shia believe that God already gave power over the entire universe to the Imams, so I mean their argument is literally 'it's not shirk unless you believe they got God's power themselves', and that's just stupid.
