Blank mayavi.mlab scene

I created a fresh conda environment with:
`conda create -n pymayavi python=3.7 vtk=8 pyqt=5`
then
`conda activate pymayavi`
`conda install mayavi`
This creates an environment with:
```
$ conda list:
# packages in environment at /Users/matthiasf/opt/miniconda3/envs/pymayavi:
#
# Name Version Build Channel
apptools 5.1.0 pyh44b312d_0 conda-forge
bzip2 1.0.8 hc929b4f_4 conda-forge
c-ares 1.17.1 h0d85af4_1 conda-forge
ca-certificates 2020.12.5 h033912b_0 conda-forge
certifi 2020.12.5 py37hf985489_1 conda-forge
configobj 5.0.6 py_0 conda-forge
curl 7.75.0 h06286d4_0 conda-forge
dbus 1.13.6 h0c50699_1 conda-forge
envisage 4.9.2 pyh9f0ad1d_1 conda-forge
expat 2.2.10 h1c7c35f_0 conda-forge
freetype 2.10.4 h4cff582_1 conda-forge
future 0.18.2 py37hf985489_3 conda-forge
gettext 0.19.8.1 h7937167_1005 conda-forge
glib 2.66.7 he49afe7_1 conda-forge
glib-tools 2.66.7 he49afe7_1 conda-forge
hdf4 4.2.13 h71d84a9_1004 conda-forge
hdf5 1.10.6 nompi_h34ad4e8_1111 conda-forge
icu 64.2 h6de7cb9_1 conda-forge
jpeg 9d hbcb3906_0 conda-forge
jsoncpp 1.8.4 ha1b3eb9_1002 conda-forge
krb5 1.17.2 h60d9502_0 conda-forge
libblas 3.9.0 8_openblas conda-forge
libcblas 3.9.0 8_openblas conda-forge
libcurl 7.75.0 h8ef9fac_0 conda-forge
libcxx 11.1.0 habf9029_0 conda-forge
libedit 3.1.20191231 h0678c8f_2 conda-forge
libev 4.33 haf1e3a3_1 conda-forge
libffi 3.3 h046ec9c_2 conda-forge
libgfortran 4.0.0 7_5_0_h1a10cd1_19 conda-forge
libgfortran4 7.5.0 h1a10cd1_19 conda-forge
libglib 2.66.7 hd556434_1 conda-forge
libiconv 1.16 haf1e3a3_0 conda-forge
liblapack 3.9.0 8_openblas conda-forge
libnetcdf 4.7.4 nompi_h9d8a93f_107 conda-forge
libnghttp2 1.43.0 h07e645a_0 conda-forge
libopenblas 0.3.12 openmp_h63d9170_1 conda-forge
libpng 1.6.37 h7cec526_2 conda-forge
libssh2 1.9.0 h8a08a2b_5 conda-forge
libtiff 4.2.0 h355d032_0 conda-forge
libwebp-base 1.2.0 hbcf498f_0 conda-forge
libxml2 2.9.10 h53d96d6_0 conda-forge
llvm-openmp 11.0.1 h7c73e74_0 conda-forge
lz4-c 1.9.2 hb1e8313_3 conda-forge
mayavi 4.7.2 py37h0231a1f_1 conda-forge
ncurses 6.2 h2e338ed_4 conda-forge
numpy 1.20.1 py37ha9839cc_0 conda-forge
openssl 1.1.1j hbcf498f_0 conda-forge
pcre 8.44 hb1e8313_0 conda-forge
pip 21.0.1 pyhd8ed1ab_0 conda-forge
pyface 7.3.0 pyh44b312d_0 conda-forge
pygments 2.8.0 pyhd8ed1ab_0 conda-forge
pyqt 5.9.2 py37h2a560b1_4 conda-forge
python 3.7.10 h7728216_100_cpython conda-forge
python_abi 3.7 1_cp37m conda-forge
qt 5.9.7 h8cf7e54_3 conda-forge
readline 8.0 h0678c8f_2 conda-forge
setuptools 49.6.0 py37hf985489_3 conda-forge
sip 4.19.8 py37h0a44026_0
six 1.15.0 pyh9f0ad1d_0 conda-forge
sqlite 3.34.0 h17101e1_0 conda-forge
tbb 2020.2 h940c156_4 conda-forge
tk 8.6.10 h0419947_1 conda-forge
traits 6.2.0 py37hf967b71_0 conda-forge
traitsui 7.1.0 pyh9f0ad1d_0 conda-forge
vtk 8.2.0 py37hd5eadda_218 conda-forge
wheel 0.36.2 pyhd3deb0d_0 conda-forge
xz 5.2.5 haf1e3a3_1 conda-forge
zlib 1.2.11 h7795811_1010 conda-forge
zstd 1.4.5 h41d2c2f_0
```
Upon running a python mlab script (simply plotting a 3D point cloud with mlab.points3d()):
```
import mayavi.mlab as mlab
import numpy as np

data = np.array([[0, 0, 0], [1, 1, 1]])

mlab.figure()
mlab.points3d(data)
mlab.show()
```
this runs into ImportErrors of:
```
ModuleNotFoundError: No module named 'importlib_metadata'
```
and
```
ModuleNotFoundError: No module named 'importlib_resources'
```
After installing both of these, I still don't have a working mayavi.mlab environment, as the example above spawns a blank mayavi scene. The buttons on the top are unresponsive.
Setting then the environment variables:
```
export QT_API=pyqt
export ETS_TOOLKIT=qt5
```
Results in:
```
RuntimeError: No pyface.toolkits plugin found for toolkit qt5
```

What might be the issue here?

It's weird as I remember this working a couple months ago (although, granted, I do not have the package list from that time).