Warnings() in functions sf package

I'm running the code below and I get several "warnings". I used the sf_use_s2(FALSE) function to work with plane coordinates following the old way of the 'sf' package but even so I keep getting some warnings that I didn't get before.

##locations####
#import dataframes and joining
loc <-
  list.files(path = "./dados",
             pattern = "*.csv", 
             full.names = T) %>% 
  purrr::map_df(~readr::read_csv(.)) 

############################ HEXAGON GRID ########################################
sf_use_s2(FALSE) #assume plane coordinates

#convert locations to obj sf
loc.sf <- loc %>% 
  sf::st_as_sf(coords = c("x", "y"), crs = 4326)

#hexagon grid
grid = sf::st_make_grid(sf::st_bbox(loc.sf),
                        cellsize = .1, square = FALSE) %>%
  sf::st_as_sf() 

#import brazil shp
brasil <- sf::st_read(here::here("shps", "BR_UF_2020.shp")) %>%
  sf::st_transform(4326) %>% sf::st_union() %>% sf::st_as_sf()

#simplify geometry
brasil1<- sf::st_simplify(brasil, 
                          preserveTopology = FALSE, 
                          dTolerance = 0.05) %>% sf::st_as_sf()

#import zee shp
zee <- sf::st_read(here::here("shps", "zeee.shp")) %>% 
  sf::st_union() %>% sf::st_as_sf()

#simplify geometry
zee1<- sf::st_simplify(zee, 
                       preserveTopology = FALSE, 
                       dTolerance = 0.05) %>% sf::st_as_sf()

#crop grid by linecoast
grid1 <- sf::st_difference(grid, brasil1) %>% sf::st_as_sf()

#crop grid by zee limit
grid2 <- sf::st_intersection(grid1, zee1) %>% sf::st_as_sf()


#filter locations by zee limit
loc <- sf::st_intersection(zee1, loc.sf)

WARNINGS:

In st_simplify.sfc(st_geometry(x), preserveTopology, dTolerance) :
st_simplify does not correctly simplify longitude/latitude data,
dTolerance needs to be in decimal degrees

- 

although coordinates are longitude/latitude, st_intersection assumes that they are planar
Warning message:
attribute variables are assumed to be spatially constant throughout all geometries